Andrew C Comrie

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Books

• Comrie, A. C. (2021). Like Nobody’s Business: An Insider’s Guide to How US University Finances Really Work. Cambridge, UK: Open Book Publishers. doi:10.11647/OBP.0240
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  How do university finances really work?From flagship public research universities to small, private liberal arts colleges, there are few aspects of these institutions associated with more confusion, myths or lack of understanding than how they fund themselves and function in the business of higher education. Using simple, approachable explanations supported by clear illustrations, this book takes the reader on an engaging and enlightening tour of how the money flows. How does the university really pay for itself? Why do tuition and fees rise so fast? Why do universities lose money on research? Do most donations go to athletics?Grounded in hard data, original analyses, and the practical experience of a seasoned administrator, this book provides refreshingly clear answers and comprehensive insights for anyone on or off campus who is interested in the business of the university: how it earns its money, how it spends it, and how it all works.
• Comrie, A. C. (2021). Like nobody's business: An insider's guide to how US University finances really work. Open Book Publishers. doi:10.11647/obp.0240
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  From flagship public research universities to small, private liberal arts colleges, there are few aspects of these institutions associated with more confusion, myths or lack of understanding than how they fund themselves and function in the business of higher education. Using simple, approachable explanations supported by clear illustrations, this book takes the reader on an engaging and enlightening tour of how the money flows. How does the university really pay for itself? Why do tuition and fees rise so fast? Why do universities lose money on research? Do most donations go to athletics? Grounded in hard data, original analyses, and the practical experience of a seasoned administrator, this book provides refreshingly clear answers and comprehensive insights for anyone on or off campus who is interested in the business of the university: how it earns its money, how it spends it, and how it all works.

Chapters

• Comrie, A. (2021). 7. Student Affairs. In Like Nobody’s Business: An Insider’s Guide to How US University Finances Really Work(pp 165-200). Open Book Publishers. doi:10.11647/obp.0240.07
• Comrie, A. (2021). 9. Public Service, Cooperative Extension, and Community Engagement. In Like Nobody’s Business: An Insider’s Guide to How US University Finances Really Work(pp 223-240). Open Book Publishers. doi:10.11647/obp.0240.09
• Comrie, A. (2021). Epilogue. In Like Nobody’s Business: An Insider’s Guide to How US University Finances Really Work(pp 349-350). Open Book Publishers. doi:10.11647/obp.0240.15
• Brown, H. E., Comrie, A. C., Tamerius, J., Khan, M., Tabor, J. A., & Galgiani, J. N. (2014). Climate, wind storms, and the risk of valley fever (coccidioidomycosis). In The Influence of Global Environmental Change on Infectious Disease Dynamics(pp Chapter A12). Washington, D.C.: The National Academies Press.
• Garfin, G. M., Franco, G., Blanco, H., Comrie, A. C., Gonzalez, P., Piechota, T., Smyth, R., & Waskom, R. (2014). Ch. 20: Southwest. In Climate Change Impacts in the United States: The Third National Climate Assessment. J.M. Melillo, T.C. Richmond, and G.W. Yohe (eds.)(pp 462-486, doi:10.7930/J08G8HMN). Washington, D.C.: U.S. Global Change Research Program.
• Yool, S. R., & Comrie, A. C. (2014). A taste of place: environmental geographies of the classic beer styles. In The Geography of Beer(pp tbd). Springer.
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  The environmental geographies of beer can be viewed as a coupling of Earth's elements (yeast; hops; malt; water) and brewing ingenuity. Yeast literally brings life to beer, contributing distinctive flavors and frothiness. Hops do best at cooler latitudes, and in wetter climates, where soils, day length, temperature, rainfall and terrain all influence regional hop characteristics. Brewing malts are cultivated, mostly, in a cool swath of countries just poleward of 45 degrees north latitude. Mixtures of minerals found in local water supplies impart characteristic flavors and mouth feel to beers brewed there. The geographic combination of variations in yeast, hops, malt and water produce, we argue, a "taste of the place" that one can term the "terroir" of beer. Climate change could, however, modify beer terroir. A warming planet would alter the latitudinal range of future hop and malt cultivation, leading to changes in supplies, quality, and prices.
• Brown, H. E., Comrie, A. C., Drechsler, D. M., Barker, C. M., Basu, R., Brown, T., Gershunov, A., Marm Kilpatrick, A., Reisen, W. K., Ruddell, D. M., & English, P. B. (2013). Human health. In Assessment of Climate Change in the Southwest United States: a Report Prepared for the National Climate Assessment. Island Press-Center for Resource Economics. doi:10.5822/978-1-61091-484-0_15
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  Global climate models project changes in precipitation patterns, drought, flooding, and sea-level rise, and an increase in the frequency, duration, and intensity of extreme heat events throughout the Southwest. The challenge for the protection of public health is to characterize how these climate events may influence health and to establish plans for mitigating and responding to the health impacts. However, the effects of climate change on health vary across the region, by population, and by disease system, making it difficult to establish broad yet concise health promotion messages that are useful for developing adaptation and mitigation plans. Techniques are increasingly available to quantify the health effects resulting from climate change and to move forward into predictions that are of sufficient resolution to establish policy guidelines. Strides are being made in assigning cost to both the positive and negative effects on health of proposed climate-mitigation strategies or the lack thereof. As a result, more tools are available for cities and states to develop mitigation and adaptation plans that are specifically tailored to their populations.
• Brown, H. E., Comrie, A. C., Drechsler, D., Barker, C. M., Basu, R., Brown, T., Gershunov, A., Reisen, W. K., & Ruddell, D. (2013). Health Effects of Climate Change in the Southwest. In Assessment of Climate Change in the Southwest United States: a Technical Report Prepared for the U.S. National Climate Assessment.(pp 312-339). Southwest Climate Alliance.
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  Review Editor: English, P. Health Effects of Climate Change in the Southwest. Chapter 15, in: Assessment of Climate Change in the Southwest United States: a Technical Report Prepared for the U.S. National Climate Assessment. A report by the Southwest Climate Alliance [Garfin, G., Jardine, A., Merideth, R., Black, M., and Overpeck, J. (eds.)]. 2013, Tucson, AZ: Southwest Climate Alliance.
• Peters, D. P., Bestelmeyer, B. T., Havstad, K. M., Rango, A., Archer, S. R., Comrie, A. C., Gimblett, H. R., López-Hoffman, L., Sala, O. E., Vivoni, E. R., Brooks, M. L., Brown, J., Monger, H. C., Goldstein, J. H., Okin, G. S., & Tweedie, C. E. (2013). Desertification of Rangelands. In Climate Vulnerability: Understanding and Addressing Threats to Essential Resources. Elsevier Inc. doi:10.1016/b978-0-12-384703-4.00426-3
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  Desertification, the broad-scale conversion of perennial grasslands to dominance by annuals or xerophytic shrubs, has affected drylands globally over the past several centuries. Desertification is a cumulative threat that includes both climatic (e.g., drought) and land-use drivers (e.g., livestock overgrazing, fire). In this chapter, we determine the vulnerability of different ecosystem services to changes in drivers and ecosystem states, with a focus on the American Southwest. We have four objectives: (1) to describe key services in drylands, (2) to identify consequences of desertification to each service, (3) to explore the vulnerability of each service to future state-changes if existing threats intensify and new threats emerge, and (4) to determine threats expected to have the greatest future impact, and to provide potential actions for mitigation. We conclude with recommendations. © 2013 Elsevier Inc. All rights reserved.
• Peters, D., Bestelmeyer, B. T., Havstad, K. M., Rango, A., Archer, S. R., Comrie, A. C., Gimblett, H. R., López-Hoffman, L., Sala, O. E., Vivoni, E. R., Brooks, M. L., Brown, J., Monger, H. C., Goldstein, J. H., Okin, G. S., Tweedie, C. E., & Pielke, R. A. (2013). 4.20 - Desertification of Rangelands. In Climate Vulnerability: Understanding and Addressing Threats to Essential Resources(pp 239-258). Academic Press.
• Yool, S., & Comrie, A. (2013). A taste of place: Environmental geographies of the classic beer styles. In The Geography of Beer. Springer Netherlands. doi:10.1007/978-94-007-7787-3_10
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  The environmental geographies of beer can be viewed as a coupling of Earth's elements (yeast; hops; malt; water) and brewing ingenuity. Yeast literally brings life to beer, contributing distinctive flavors and frothiness. Hops do best at cooler latitudes, and in wetter climates, where soils, day length, temperature, rainfall and terrain all influence regional hop characteristics. Brewing malts are cultivated, mostly, in a cool swath of countries just poleward of 45° north latitude. Mixtures of minerals found in local water supplies impart characteristic flavors and mouth feel to beers brewed there. The geographic combination of variations in yeast, hops, malt and water produce, we argue, a 'taste of the place' that one can term the 'terroir' of beer. Climate change could, however, modify beer terroir. A warming planet would alter the latitudinal range of future hop and malt cultivation, leading to changes in supplies, quality, and prices.
• Hudspeth, W., Reisen, W. K., Barker, C. M., Kramer, V., Caian, M., Crăciunescu, V., Brown, H. E., Comrie, A. C., Zelicoff, A., Ward, T. G., Ragain, R. M., Simpson, G., Stanhope, W., Kass-Hout, T. A., Scharl, A., Sonricker, A. L., & Brownstein, J. S. (2012). Information and decision support systems. In Environmental Tracking for Public Health Surveillance. CRC Press.
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  This chapter describes various approaches for extending environmental observations into actionable public health decisions.
• Reisen, W. K., Barker, C. M., Kramer, V. K., Caian, M., Hudspeth, W., Morain, S., Budge, A., Glass, G., Brown, H. E., & Comrie, A. C. (2012). Information and decision support systems. In Environmental Tracking for Public Health Surveillance(p. 369). CRC Press.
• Sorrensen, C., & Comrie, A. (2009). Urbanization and hydroclimatic challenges in the Sonoran Desert Border region. In Sustainable Communities on a Sustainable Planet: The Human Environment Regional Observatory Project. Cambridge University Press. doi:10.1017/cbo9780511635694.014
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  Introduction: The Sonoran Desert Border Region HERO consists of two watersheds, the Santa Cruz River and the San Pedro River, as well as the counties and municipalities predominantly situated in these watersheds. Both watersheds straddle the United States-Mexico border with their rivers flowing north from Sonora, Mexico into Arizona, United States. On the Arizona side, Santa Cruz and Cochise Counties reside mainly in these basins and rely on the groundwater sources within the basins. On the Sonoran side, there are five municipalities: Nogales and Santa Cruz in the Santa Cruz Basin, and Cananea, Naco, and Agua Prieta in the San Pedro Basin. Most of the population in this border region lives in two urban transborder communities: Nogales, Arizona and Nogales, Sonora, situated on the western side of the study area and together referred to as Ambos Nogales; and Douglas, Arizona and Agua Prieta, Sonora situated on the eastern side. A third transborder community, Naco, Arizona and Naco, Sonora, located just west of Douglas/Agua Prieta, is very small. Other settlements of significant size dot the region, including Sierra Vista, Rio Rico, Douglas, and Benson on the Arizona side, and Santa Cruz and Cananea on the Sonoran side (Figure 14.1). The Sonoran Desert Border Region is semi-arid to arid, with summer temperatures frequently reaching over 104¼;F (40¼C). The region experiences bimodal winter/summer precipitation patterns resulting from midlatitude frontal systems in winter and from thunderstorms within the regional North American monsoon circulation in summer (Adams and Comrie 1997; Sheppard et al. 2002).

Journals/Publications

• Arora, M., Comrie, A. C., & Ernst, K. E. (2023). Assessing climate and health curriculum in graduate public health education in the United States. Frontiers in Public Health, 11(Issue). doi:10.3389/fpubh.2023.1124379
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  Climate change has been identified as both a challenge and an opportunity for public health. The onus to prepare the next generation of public health practitioners lies heavily on schools and programs of public health. This article (i) assesses the status of climate change and health curricula in accredited schools of public health in the United States and (ii) proposes strategies to better train professionals so they are more informed and prepared to mitigate, manage, and respond to the health impacts of climate change. Course offerings and syllabi listed in online course catalogs from 90 nationally accredited schools of public health were evaluated with the purpose of identifying the extent of climate change education in graduate programs. Only 44 public health institutions were found to offer a climate change related course at the graduate level of education. Of the 103 courses identified, approximately 50% (n = 46) are focused on this climate change and health. These courses cover a wide array of topics with an emphasis on conveying fundamental concepts. In-depth assessment revealed a need for integrating learning opportunities that build practical skills useful in a hands-on public health practice environment. This assessment indicates the limited availability of climate-health course offerings available to graduate students in accredited schools. The findings are used to propose an educational framework to integrate climate change into public health curricula. The proposed framework, while rooted in existing directives, adopts a tiered approach that can be readily applied by institutions training the next generation of public health leaders.
• Comrie, A. C. (2021). No Consistent Link Between Dust Storms and Valley Fever (Coccidioidomycosis). GeoHealth, 5(12), e2021GH000504.
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  Dust storms, such as those associated with haboobs and strong regional winds, are frequently assumed to cause increases in cases of Valley fever (coccidioidomycosis). The disease is caused by inhaling arthroconidia of fungi that, after being disturbed from semi-desert subsoil, have become airborne. Fungal arthroconidia can be transported in low-wind conditions as well as in individual dust events, but there is no reliable evidence that all or most dust storms consistently lead to subsequent increases in coccidioidomycosis cases. Following a review of the relevant literature, this study examines the relationship between dust storms and coccidioidomycosis cases to determine if there is a consistent and general association between them. All recorded dust storms from 2006 to 2020 in and near the Phoenix area of Maricopa County, Arizona and the Bakersfield area of Kern County, California were used in a compositing analysis (superposed epoch analysis) of subsequent coccidioidomycosis cases in each area. Analyses of monthly and weekly disease case data showed no statistical differences in the patterns of coccidioidomycosis cases following dust storms versus non-dust storm conditions, for the entire data set as well as for seasonal subsets of the data. This study thoroughly analyzes post-dust storm coccidioidomycosis cases for a large set of dust storms, and it confirms and expands upon previous literature, including a recent study that measured airborne arthroconidia and found no consistent links connecting wind and dust conditions to increases in coccidioidomycosis.
• Comrie, A. C. (2021). No Consistent Link Between Dust Storms and Valley Fever (Coccidioidomycosis). GeoHealth, 5(Issue 12). doi:10.1029/2021gh000504
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  Dust storms, such as those associated with haboobs and strong regional winds, are frequently assumed to cause increases in cases of Valley fever (coccidioidomycosis). The disease is caused by inhaling arthroconidia of Coccidioides fungi that, after being disturbed from semi-desert subsoil, have become airborne. Fungal arthroconidia can be transported in low-wind conditions as well as in individual dust events, but there is no reliable evidence that all or most dust storms consistently lead to subsequent increases in coccidioidomycosis cases. Following a review of the relevant literature, this study examines the relationship between dust storms and coccidioidomycosis cases to determine if there is a consistent and general association between them. All recorded dust storms from 2006 to 2020 in and near the Phoenix area of Maricopa County, Arizona and the Bakersfield area of Kern County, California were used in a compositing analysis (superposed epoch analysis) of subsequent coccidioidomycosis cases in each area. Analyses of monthly and weekly disease case data showed no statistical differences in the patterns of coccidioidomycosis cases following dust storms versus non-dust storm conditions, for the entire data set as well as for seasonal subsets of the data. This study thoroughly analyzes post-dust storm coccidioidomycosis cases for a large set of dust storms, and it confirms and expands upon previous literature, including a recent study that measured airborne arthroconidia and found no consistent links connecting wind and dust conditions to increases in coccidioidomycosis.
• Brown, H. E., Barrera, R., Comrie, A. C., & Lega, J. (2017). Effect of Temperature Thresholds on Modeled Aedes aegypti (Diptera: Culicidae) population dynamics. Journal of Medical Entomology, 54(Issue 4). doi:10.1093/jme/tjx041
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  Dynamic simulation models provide vector abundance estimates using only meteorological data. However, model outcomes may heavily depend on the assumptions used to parameterize them. We conducted a sensitivity analysis for a model of Aedes aegypti (L.) abundance using weather data from two locations where this vector is established, La Margarita, Puerto Rico and Tucson, Arizona. We tested the effect of simplifying temperature-dependent development and mortality rates and of changing development and mortality thresholds as compared with baselines estimated using biophysical models. The simplified development and mortality rates had limited effect on abundance estimates in either location. However, in Tucson, where the vector is established but has not transmitted viruses, a difference of 5 °C resulted in populations either surviving or collapsing in the hot Arizona mid-summer, depending on the temperature thresholds. We find three important implications of the observed sensitivity to temperature thresholds. First, this analysis indicates the need for better estimates of the temperature tolerance thresholds to refine entomologic risk mapping for disease vectors. Second, our results highlight the importance of extreme temperatures on vector survival at the marginal areas of this vector's distribution. Finally, the model suggests that adaptation to warmer temperatures may shift regions of pathogen transmission.
• Brown, H. E., Cox, J. T., Comrie, A. C., & Barrera, R. (2017). Habitat and density of oviposition opportunity influences Aedes aegypti (Diptera: Culicidae) flight distance. Journal of Medical Entomology, 54(5), 1385–1389. doi:https://doi.org/10.1093/jme/tjx083
• Brown, H. E., Cox, J., Comrie, A. C., & Barrera, R. (2017). Habitat and density of oviposition opportunity influences Aedes aegypti (Diptera: Culicidae) flight distance. Journal of Medical Entomology, 54(Issue 5). doi:10.1093/jme/tjx083
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  Understanding the dispersal of Aedes (aegypti (L.) Diptera: Culicidae) after consuming a potentially infectious bloodmeal is an important part of controlling the spread of the arboviruses it transmits. Because of the impact on abundance, removal of oviposition sites is a key component of vector control. However, source reduction around a case may encourage dispersal of potentially infected vectors. We compare the effect of oviposition site availability on Ae. aegypti dispersal behavior within 30-m linear cages in three model ecosystems at the University of Arizona's Biosphere 2 research facility. We found a significant interaction effect in which, when oviposition site density was sparse, dispersal was greater in the highly vegetated humid rainforest and limited in the low vegetation, arid desert model ecosystem. When oviposition site density was dense, no significant effect on dispersal was observed. These analyses support the idea that source reduction has an important influence on the distance that gravid, potentially infected, females will travel.
• Brown, H. E., Lega, J. C., Barrera, R., Comrie, A. C., Barrera, R., Comrie, A. C., Lega, J. C., & Brown, H. E. (2017). Effect of temperature thresholds on modeled Aedes aegypti population dynamics. Journal of Medical Entomology, 54(4), 869–877. doi:https://doi.org/10.1093/jme/tjx041
• Butterworth, M. K., Morin, C. W., & Comrie, A. C. (2017). An Analysis of the Potential Impact of Climate Change on Dengue Transmission in the Southeastern United States. Environmental health perspectives, 125(4), 579-585.
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  Dengue fever, caused by a mosquito-transmitted virus, is an increasing health concern in the Americas. Meteorological variables such as temperature and precipitation can affect disease distribution and abundance through biophysical impacts on the vector and on the virus. Such tightly coupled links may facilitate further spread of dengue fever under a changing climate. In the southeastern United States, the dengue vector is widely established and exists on the current fringe of dengue transmission.
• Butterworth, M. K., Morin, C. W., & Comrie, A. C. (2017). An analysis of the potential impact of climate change on dengue transmission in the southeastern United States. Environmental Health Perspectives, 125(Issue 4). doi:10.1289/ehp218
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  Background: Dengue fever, caused by a mosquito-transmitted virus, is an increasing health concern in the Americas. Meteorological variables such as temperature and precipitation can affect disease distribution and abundance through biophysical impacts on the vector and on the virus. Such tightly coupled links may facilitate further spread of dengue fever under a changing climate. In the southeastern United States, the dengue vector is widely established and exists on the current fringe of dengue transmission. Objectives: We assessed projected climate change–driven shifts in dengue transmission risk in this region. Methods: We used a dynamic mosquito population and virus transmission model driven by meteorological data to simulate Aedes aegypti populations and dengue cases in 23 locations in the southeastern United States under current climate conditions and future climate projections. We compared estimates for each location with simulations based on observed data from San Juan, Puerto Rico, where dengue is endemic. Results: Our simulations based on current climate data suggest that dengue transmission at levels similar to those in San Juan is possible at several U.S. locations during the summer months, particularly in southern Florida and Texas. Simulations that include climate change projections suggest that conditions may become suitable for virus transmission in a larger number of locations and for a longer period of time during each year. However, in contrast with San Juan, U.S. locations would not sustain year-round dengue transmission according to our model. Conclusions: Our findings suggest that Dengue virus (DENV) transmission is limited by low winter temperatures in the mainland United States, which are likely to prevent its permanent establishment. Although future climate conditions may increase the length of the mosquito season in many locations, projected increases in dengue transmission are limited to the southernmost locations.
• Brown, H. E., Young, A., Lega, J., Andreadis, T. G., Schurich, J., & Comrie, A. (2015). Projection of Climate Change Influences on U.S. West Nile Virus Vectors. Earth interactions, 19.
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  While estimates of the impact of climate change on health are necessary for health care planners and climate change policy makers, models to produce quantitative estimates remain scarce. We describe a freely available dynamic simulation model parameterized for three West Nile virus vectors, which provides an effective tool for studying vector-borne disease risk due to climate change. The Dynamic Mosquito Simulation Model is parameterized with species specific temperature-dependent development and mortality rates. Using downscaled daily weather data, we estimate mosquito population dynamics under current and projected future climate scenarios for multiple locations across the country. Trends in mosquito abundance were variable by location, however, an extension of the vector activity periods, and by extension disease risk, was almost uniformly observed. Importantly, mid-summer decreases in abundance may be off-set by shorter extrinsic incubation periods resulting in a greater proportion of infective mosquitoes. Quantitative descriptions of the effect of temperature on the virus and mosquito are critical to developing models of future disease risk.
• Brown, H. E., Young, A., Lega, J., Andreadis, T. G., Schurich, J., & Comrie, A. (2015). Projection of climate change influences on U.S. West nile virus vectors. Earth Interactions, 19(Issue 18). doi:10.1175/ei-d-15-0008.1
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  While estimates of the impact of climate change on health are necessary for health care planners and climate change policy makers, models to produce quantitative estimates remain scarce. This study describes a freely available dynamic simulation model parameterized for three West Nile virus vectors, which provides an effective tool for studying vectorborne disease risk due to climate change. The Dynamic Mosquito Simulation Model is parameterized with species-specific temperature-dependent development and mortality rates. Using downscaled daily weather data, this study estimates mosquito population dynamics under current and projected future climate scenarios for multiple locations across the country. Trends in mosquito abundance were variable by location; however, an extension of the vector activity periods, and by extension disease risk, was almost uniformly observed. Importantly, midsummer decreases in abundance may be offset by shorter extrinsic incubation periods, resulting in a greater proportion of infective mosquitoes. Quantitative descriptions of the effect of temperature on the virus and mosquito are critical to developing models of future disease risk.
• Comrie, A. C., & McCabe, G. J. (2013). Global air temperature variability independent of sea-surface temperature influences. Progress in Physical Geography, 37(1), 29--35.
• Delgado, S., Ernst, K. C., Pumahuaca, M. L., Yool, S. R., Comrie, A. C., Sterling, C. R., Gilman, R., Naquira, C., & Levy, M. (2013). A country bug in the city: urban infestation by the Chagas disease vector Triatoma infestans in Arequipa, Peru. International Journal of Health Geographics.
• Delgado, S., Ernst, K. C., Pumahuanca, M. L., Yool, S. R., Comrie, A. C., Sterling, C. R., Gilman, R. H., Náquira, C., & Levy, M. Z. (2013). A country bug in the city: Urban infestation by the Chagas disease vector Triatoma infestans in Arequipa, Peru. International Journal of Health Geographics, 12(Issue). doi:10.1186/1476-072x-12-48
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  Background: Interruption of vector-borne transmission of Trypanosoma cruzi remains an unrealized objective in many Latin American countries. The task of vector control is complicated by the emergence of vector insects in urban areas.Methods: Utilizing data from a large-scale vector control program in Arequipa, Peru, we explored the spatial patterns of infestation by Triatoma infestans in an urban and peri-urban landscape. Multilevel logistic regression was utilized to assess the associations between household infestation and household- and locality-level socio-environmental measures.Results: Of 37,229 households inspected for infestation, 6,982 (18.8%; 95% CI: 18.4 - 19.2%) were infested by T. infestans. Eighty clusters of infestation were identified, ranging in area from 0.1 to 68.7 hectares and containing as few as one and as many as 1,139 infested households. Spatial dependence between infested households was significant at distances up to 2,000 meters. Household T. infestans infestation was associated with household- and locality-level factors, including housing density, elevation, land surface temperature, and locality type.Conclusions: High levels of T. infestans infestation, characterized by spatial heterogeneity, were found across extensive urban and peri-urban areas prior to vector control. Several environmental and social factors, which may directly or indirectly influence the biology and behavior of T. infestans, were associated with infestation. Spatial clustering of infestation in the urban context may both challenge and inform surveillance and control of vector reemergence after insecticide intervention. © 2013 Delgado et al.; licensee BioMed Central Ltd.
• El Vilaly, A. E., Arora, M., Butterworth, M. K., El Vilaly, M. A., Jarnagin, W., & Comrie, A. C. (2013). Climate, environment and disease: The case of Rift Valley fever. Progress in Physical Geography, 37(Issue 2). doi:10.1177/0309133313478315
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  Rift Valley fever is a disease of animals and humans found throughout much of Africa, and recently in the Arabian Peninsula. It is spread via mosquito vectors and direct contact with infected tissue and fluids. Climate variability and change alter ecological processes involved in the outbreak and spread of diseases such as Rift Valley fever. This progress report reviews the key research literature on climate-driven environmental change and Rift Valley fever. The roles of regional and seasonal climates for the disease are emphasized, as well as remote sensing and other approaches to monitoring and analysis. The paper concludes with five suggested future directions for research. © The Author(s) 2013.
• El Vilaly, A. E., Arora, M., Butterworth, M. K., Jarnagin, W., Comrie, A. C., & others, . (2013). Climate, environment and disease: The case of Rift Valley fever. Progress in Physical Geography, 37(2), 259--269.
• Morin, C. W., & Comrie, A. C. (2013). Regional and seasonal response of a West Nile virus vector to climate change. Proceedings of the National Academy of Sciences of the United States of America, 110(39).
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  Climate change will affect the abundance and seasonality of West Nile virus (WNV) vectors, altering the risk of virus transmission to humans. Using downscaled general circulation model output, we calculate a WNV vector's response to climate change across the southern United States using process-based modeling. In the eastern United States, Culex quinquefasciatus response to projected climate change displays a latitudinal and elevational gradient. Projected summer population depressions as a result of increased immature mortality and habitat drying are most severe in the south and almost absent further north; extended spring and fall survival is ubiquitous. Much of California also exhibits a bimodal pattern. Projected onset of mosquito season is delayed in the southwestern United States because of extremely dry and hot spring and summers; however, increased temperature and late summer and fall rains extend the mosquito season. These results are unique in being a broad-scale calculation of the projected impacts of climate change on a WNV vector. The results show that, despite projected widespread future warming, the future seasonal response of C. quinquefasciatus populations across the southern United States will not be homogeneous, and will depend on specific combinations of local and regional conditions.
• Morin, C. W., & Comrie, A. C. (2013). Regional and seasonal response of a West Nile virus vector to climate change. Proceedings of the National Academy of Sciences of the United States of America, 110(Issue 39). doi:10.1073/pnas.1307135110
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  Climate change will affect the abundance and seasonality of West Nile virus (WNV) vectors, altering the risk of virus transmission to humans. Using downscaled general circulation model output, we calculate a WNV vector's response to climate change across the southern United States using process-based modeling. In the eastern United States, Culex quinquefasciatus response to projected climate change displays a latitudinal and elevational gradient. Projected summer population depressions as a result of increased immature mortality and habitat drying are most severe in the south and almost absent further north; extended spring and fall survival is ubiquitous. Much of California also exhibits a bimodal pattern. Projected onset of mosquito season is delayed in the southwestern United States because of extremely dry and hot spring and summers; however, increased temperature and late summer and fall rains extend the mosquito season. These results are unique in being a broad-scale calculation of the projected impacts of climate change on a WNV vector. The results show that, despite projected widespread future warming, the future seasonal response of C. Quinquefasciatus populations across the southern United States will not be homogeneous, and will depend on specific combinations of local and regional conditions.
• Morin, C. W., Comrie, A. C., & Ernst, K. C. (2013). Climate and dengue transmission: evidence and implications. Environmental health perspectives, 121(11-12), 1264-72. doi:http://dx.doi.org/10.1289/ehp.1306556
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  Climate influences dengue ecology by affecting vector dynamics, agent development, and mosquito/human interactions. Although these relationships are known, the impact climate change will have on transmission is unclear. Climate-driven statistical and process-based models are being used to refine our knowledge of these relationships and predict the effects of projected climate change on dengue fever occurrence, but results have been inconsistent.
• Tamerius, J. D., Shaman, J., Alonso, W. J., Bloom-Feshbach, K., Uejio, C. K., Comrie, A., & Viboud, C. (2013). Environmental Predictors of Seasonal Influenza Epidemics across Temperate and Tropical Climates. PLoS Pathogens, 9(Issue 3). doi:10.1371/journal.ppat.1003194
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  Human influenza infections exhibit a strong seasonal cycle in temperate regions. Recent laboratory and epidemiological evidence suggests that low specific humidity conditions facilitate the airborne survival and transmission of the influenza virus in temperate regions, resulting in annual winter epidemics. However, this relationship is unlikely to account for the epidemiology of influenza in tropical and subtropical regions where epidemics often occur during the rainy season or transmit year-round without a well-defined season. We assessed the role of specific humidity and other local climatic variables on influenza virus seasonality by modeling epidemiological and climatic information from 78 study sites sampled globally. We substantiated that there are two types of environmental conditions associated with seasonal influenza epidemics: "cold-dry" and "humid-rainy". For sites where monthly average specific humidity or temperature decreases below thresholds of approximately 11-12 g/kg and 18-21°C during the year, influenza activity peaks during the cold-dry season (i.e., winter) when specific humidity and temperature are at minimal levels. For sites where specific humidity and temperature do not decrease below these thresholds, seasonal influenza activity is more likely to peak in months when average precipitation totals are maximal and greater than 150 mm per month. These findings provide a simple climate-based model rooted in empirical data that accounts for the diversity of seasonal influenza patterns observed across temperate, subtropical and tropical climates.
• Tamerius, J. D., Shaman, J., Alonso, W. J., Bloom-Feshbach, K., Uejio, C. K., Comrie, A., & Viboud, C. (2013). Environmental predictors of seasonal influenza epidemics across temperate and tropical climates. PLoS pathogens, 9(3), e1003194.
• Comrie, A. C., & McCabe, G. J. (2012). Global air temperature variability independent of sea-surface temperature influences. Progress in Physical Geography: Earth and Environment, 37(1), 29-35. doi:10.1177/0309133312460074
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  Mean global surface air temperature (SAT) and sea surface temperature (SST) display substantial variability on timescales ranging from annual to multi-decadal. We review the key recent literature on connections between global SAT and SST variability. Although individual ocean influences on SAT have been recognized, the combined contributions of worldwide SST variability on the global SAT signal have not been clearly identified in observed data. We analyze these relations using principal components of detrended SST, and find that removing the underlying combined annual, decadal, and multi-decadal SST variability from the SAT time series reveals a nearly monotonic global warming trend in SAT since about 1900.
• Scott, C. A., Robbins, P. F., & Comrie, A. C. (2012). The Mutual Conditioning of Humans and Pathogens: Implications for Integrative Geographical Scholarship. Annals of the Association of American Geographers, 102(Issue 5). doi:10.1080/00045608.2012.657511
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  We highlight an emerging mode of human-environment enquiry that is executed by cross-disciplinary teams, spurs innovation of hybrid methods, and leads to nonintuitive findings relevant beyond disciplinary framings or specific cases. The extension of this approach in health geography is particularly instructive. By focusing on material objects like soils, insects, or sewage, researchers from diverse epistemologies are compelled to translate conceptual models of disease causation, risk, and vulnerability. Humans and pathogens mutually condition one another, a result of continuously changing exposures (settlement and development patterns that modify pathogen and vector ecology) and institutional processes (legal, economic, and organizational contexts in which environments are modified and agents respond to risk). The dynamic interactions of pathogen ecologies and human institutions produce a type of coevolution, as evidenced by three cases we consider: bacteriological and helminth infections from urban wastewater irrigation, West Nile virus and its mosquito vector in the built environment, and Valley Fever and fungal distribution under changing climate and land disturbance. Place-based, contextual exposure pathways are shown to provide only a partial explanation of disease transmission and must be complemented by insights into individual and organizational agents' motivations, logics, and responses. The object in its context holds the key to understanding the intersection between physical and environmental, and human and governance geographies. Interactively identifying and pursuing theoretical and applied challenges in this manner allows researchers to move beyond entrenched subdisciplinary understandings to frame new supradisciplinary questions. © 2012 Copyright Taylor and Francis Group, LLC.
• Scott, C. A., Robbins, P. F., & Comrie, A. C. (2012). The mutual conditioning of humans and pathogens: Implications for integrative geographical scholarship. Annals of the Association of American Geographers, 102(5), 977--985.
• Stacy, P. K., Comrie, A. C., & Yool, S. R. (2012). Modeling valley fever incidence in Arizona using a satellite-derived soil moisture proxy. GIScience & Remote Sensing, 49(2), 299--316.
• Stacy, P., Comrie, A., & Yool, S. (2012). Modeling Valley Fever incidence in Arizona using a satellite-derived soil moisture proxy. GIScience and Remote Sensing, 49(Issue 2). doi:10.2747/1548-1603.49.2.299
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  Valley Fever is caused by inhalation of spores from the soil-dwelling fungus Coccidioides spp. Pima, Pinal, and Maricopa counties, Arizona, have the highest Valley Fever incidence on earth. Despite reported links between climate, habitat, disease timing, and seasonality, relationships between the fungus and its putative affinity to moist soils are poorly understood. We used Normalized Difference Vegetation Index (NDVI) time series from the Advanced Very High Resolution Radiometer (AVHRR) sensor to compare soil moisture variations with disease incidence. Results suggest moist soils in the early spring, resulting from antecedent winter precipitation, correlate with increased incidence in these counties up to a year later.
• Uejio, C. K., Kemp, A., & Comrie, A. C. (2012). Climatic controls on West Nile virus and Sindbis virus transmission and outbreaks in South Africa. Vector-Borne and Zoonotic Diseases, 12(2), 117--125.
• Uejio, C. K., Kemp, A., & Comrie, A. C. (2012). Climatic controls on west nile virus and sindbis virus transmission and outbreaks in South Africa. Vector-Borne and Zoonotic Diseases, 12(Issue 2). doi:10.1089/vbz.2011.0655
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  The processes influencing the magnitude of West Nile virus (WNV) transmission from 1 year to the next require thorough investigation. The intensity of WNV transmission is related to the dynamics and interactions between the pathogen, vector, vertebrate hosts, and environment. Climatic variability is one process that can influence interannual disease transmission. South Africa has a long WNV and Sindbis virus (SINV) record where consistent climate and disease relationships can be identified. We relate climate conditions to historic mosquito infection rates. Next, we detect similar associations with reported human outbreaks dating back to 1941. Both concurrent summer precipitation and the change in summer precipitation from the previous to the current summer were strongly associated with WNV and SINV transmission and recorded human outbreaks. Each 100 mm interannual summer precipitation change increased WNV infection rates by 0.39 WNV-positive Culex univittatus/1000 tested Cx. univittatus. An improved understanding of biotic and abiotic disease transmission dynamics may help anticipate and mitigate future outbreaks. © 2012, Mary Ann Liebert, Inc.
• Delgado, S., Neyra, R. C., Machaca, V. R., Ju\'arez, J. A., Chu, L. C., Verastegui, M. R., Apaza, G. M., Boc\'angel, C. D., Tustin, A. W., Sterling, C. R., & others, . (2011). A history of Chagas disease transmission, control, and re-emergence in peri-rural La Joya, Peru. PLoS neglected tropical diseases, 5(2), e970.
• Delgado, S., Neyra, R. C., Machaca, V. R., Juárez, J. A., Chu, L. C., Verastegui, M. R., Apaza, G. M., Bocángel, C. D., Tustin, A. W., Sterling, C. R., Comrie, A. C., Náquira, C., del Carpio, J. G., Gilman, R. H., Bern, C., & Levy, M. Z. (2011). A history of Chagas disease transmission, control, and re-emergence in peri-rural La Joya, Peru. PLoS Neglected Tropical Diseases, 5(Issue 2). doi:10.1371/journal.pntd.0000970
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  Background:The history of Chagas disease control in Peru and many other nations is marked by scattered and poorly documented vector control campaigns. The complexities of human migration and sporadic control campaigns complicate evaluation of the burden of Chagas disease and dynamics of Trypanosoma cruzi transmission.Methodology/Principal Findings:We conducted a cross-sectional serological and entomological study to evaluate temporal and spatial patterns of T. cruzi transmission in a peri-rural region of La Joya, Peru. We use a multivariate catalytic model and Bayesian methods to estimate incidence of infection over time and thereby elucidate the complex history of transmission in the area. Of 1,333 study participants, 101 (7.6%; 95% CI: 6.2-9.0%) were confirmed T. cruzi seropositive. Spatial clustering of parasitic infection was found in vector insects, but not in human cases. Expanded catalytic models suggest that transmission was interrupted in the study area in 1996 (95% credible interval: 1991-2000), with a resultant decline in the average annual incidence of infection from 0.9% (95% credible interval: 0.6-1.3%) to 0.1% (95% credible interval: 0.005-0.3%). Through a search of archival newspaper reports, we uncovered documentation of a 1995 vector control campaign, and thereby independently validated the model estimates.Conclusions/Significance:High levels of T. cruzi transmission had been ongoing in peri-rural La Joya prior to interruption of parasite transmission through a little-documented vector control campaign in 1995. Despite the efficacy of the 1995 control campaign, T. cruzi was rapidly reemerging in vector populations in La Joya, emphasizing the need for continuing surveillance and control at the rural-urban interface.
• Tamerius, J. D., & Comrie, A. C. (2011). Coccidioidomycosis incidence in Arizona predicted by seasonal precipitation. PLoS ONE, 6(Issue 6). doi:10.1371/journal.pone.0021009
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  The environmental mechanisms that determine the inter-annual and seasonal variability in incidence of coccidioidomycosis are unclear. In this study, we use Arizona coccidioidomycosis case data for 1995-2006 to generate a timeseries of monthly estimates of exposure rates in Maricopa County, AZ and Pima County, AZ. We reveal a seasonal autocorrelation structure for exposure rates in both Maricopa County and Pima County which indicates that exposure rates are strongly related from the fall to the spring. An abrupt end to this autocorrelation relationship occurs near the the onset of the summer precipitation season and increasing exposure rates related to the subsequent season. The identification of the autocorrelation structure enabled us to construct a "primary" exposure season that spans August-March and a "secondary" season that spans April-June which are then used in subsequent analyses. We show that October-December precipitation is positively associated with rates of exposure for the primary exposure season in both Maricopa County (R = 0.72, p = 0.012) and Pima County (R = 0.69, p = 0.019). In addition, exposure rates during the primary exposure seasons are negatively associated with concurrent precipitation in Maricopa (R = -0.79, p = 0.004) and Pima (R = -0.64, p = 0.019), possibly due to reduced spore dispersion. These associations enabled the generation of models to estimate exposure rates for the primary exposure season. The models explain 69% (p = 0.009) and 54% (p = 0.045) of the variance in the study period for Maricopa and Pima counties, respectively. We did not find any significant predictors for exposure rates during the secondary season. This study builds on previous studies examining the causes of temporal fluctuations in coccidioidomycosis, and corroborates the "grow and blow" hypothesis. © 2011 Tamerius, Comrie.
• Tamerius, J. D., Tamerius, J. D., Comrie, A. C., & Comrie, A. C. (2011). Coccidioidomycosis incidence in Arizona predicted by seasonal precipitation.. PLoS ONE (Public Library of Science).
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  ;Your Role: Senior Author;Full Citation: Tamerius, J.D. and Comrie, A.C., 2011: Coccidioidomycosis incidence in Arizona predicted by seasonal precipitation. PLoS ONE 6(6): e21009. doi:10.1371/journal.pone.0021009.;Electronic: Yes;Collaborative with graduate student: Yes;
• Comrie, A. C. (2010). Nietzsche's challenge to physical geography. ACME, 9(Issue 1).
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  Using the philosophy of Nietzsche as a stimulus, I aim to engage physical geographers and fellow scientists to reconsider their roles as scientists and to make their work more action-oriented and powerful. I outline the false mystique of science and the misconception of seeing science as independent of people and society. I make a case that science gains its power by the way we attach meaning to it and its findings, and that we should act on our ability to bestow that power. Through Nietzsche, I argue that we are challenged to overcome our trained tendency toward detached environmental science and instead put in place a new physical geography that includes meaning and action. We have the opportunity to do so in practical ways, by being reflexive and acknowledging the context of our science, and by finding more ways to communicate our ideas in support of action to change our world.
• Comrie, A. C. (2010). Nietzsche’s challenge to physical geography. ACME: An International E-Journal for Critical Geographies, 9(1), 34--46.
• Morin, C. W., & Comrie, A. C. (2010). Modeled response of the West Nile virus vector Culex quinquefasciatus to changing climate using the dynamic mosquito simulation model. International Journal of Biometeorology, 54(Issue 5). doi:10.1007/s00484-010-0349-6
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  Climate can strongly influence the population dynamics of disease vectors and is consequently a key component of disease ecology. Future climate change and variability may alter the location and seasonality of many disease vectors, possibly increasing the risk of disease transmission to humans. The mosquito species Culex quinquefasciatus is a concern across the southern United States because of its role as a West Nile virus vector and its affinity for urban environments. Using established relationships between atmospheric variables (temperature and precipitation) and mosquito development, we have created the Dynamic Mosquito Simulation Model (DyMSiM) to simulate Cx. quinquefasciatus population dynamics. The model is driven with climate data and validated against mosquito count data from Pasco County, Florida and Coachella Valley, California. Using 1-week and 2-week filters, mosquito trap data are reproduced well by the model (P < 0.0001). Dry environments in southern California produce different mosquito population trends than moist locations in Florida. Florida and California mosquito populations are generally temperature-limited in winter. In California, locations are water-limited through much of the year. Using future climate projection data generated by the National Center for Atmospheric Research CCSM3 general circulation model, we applied temperature and precipitation offsets to the climate data at each location to evaluate mosquito population sensitivity to possible future climate conditions. We found that temperature and precipitation shifts act interdependently to cause remarkable changes in modeled mosquito population dynamics. Impacts include a summer population decline from drying in California due to loss of immature mosquito habitats, and in Florida a decrease in late-season mosquito populations due to drier late summer conditions. © 2010 ISB.
• Morin, C. W., & Comrie, A. C. (2010). Modeled response of the West Nile virus vector Culex quinquefasciatus to changing climate using the dynamic mosquito simulation model. International journal of biometeorology, 54(5), 517--529.
• Bieda III, S. W., Castro, C. L., Mullen, S. L., Comrie, A. C., & Pytlak, E. (2009). The relationship of transient upper-level troughs to variability of the North American monsoon system.. Journal of Climate, 22(15).
• Bieda, S. W., Castro, C. L., Mullen, S. L., Comrie, A. C., & Pytlak, E. (2009). The relationship of transient upper-level troughs to variability of the North American monsoon system. Journal of Climate, 22(Issue 15). doi:10.1175/2009jcli2487.1
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  Relationships between transient upper-tropospheric troughs and warm season convective activity over the southwest United States and northern Mexico are explored. Analysis of geopotential height and vorticity fields from the North American Regional Reanalysis and cloud-to-ground lightning data indicates that the passage of mobile inverted troughs (IVs) significantly enhances convection when it coincides with the peak diurnal cycle (1800-0900 UTC) over the North American monsoon (NAM) region. The preferred tracks of IVs during early summer are related to the dominant modes of Pacific sea surface temperature (SST) variability. When La Niña-like (El Niño-like) conditions prevail in the tropical Pacific and the eastern North Pacific has a horseshoe-shaped negative (positive) SST anomaly, IVs preferentially track farther north (south) and are slightly (typically one IV) more (less) numerous. These results point to the important role that synoptic-scale disturbances play in modulating the diurnal cycle of precipitation over the NAM region and the significant impact that the statistically supported low-frequency Pacific SST anomalies exert on the occurrence and track of these synoptic transients. © 2009 American Meteorological Society.
• Comrie, A. (2007). Climate change and human health. Geography Compass, 1(3), 325--339.
• Comrie, A. C., & Glueck, M. F. (2007). Model sensitivity for assessing climatologic effects on the risk of acquiring coccidioidomycosis. Annals of the New York Academy of Sciences, 1111(1), 83--95.
• Kolivras, K. N., & Comrie, A. C. (2007). Regionalization and variability of precipitation in Hawaii. Physical Geography, 28(1), 76--96.
• Kolivras, K. N., & Comrie, A. C. (2007). Regionalization and variability of precipitation in Hawaii. Physical Geography, 28(Issue 1). doi:10.2747/0272-3646.28.1.76
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  Regions based on seasonal precipitation variability for Hawaii are determined using a principal components analysis applied to 124 stations for the period 1971-2000. Nine regions are delineated and are consistent with known precipitation patterns; leeward and windward stations are in separate regions on all islands. Within each region, the relationship between precipitation and the El Niño-Southern Oscillation (ENSO) is examined using a correlation analysis with the Southern Oscillation Index (SOI), and the Niño 3.4 and Niño 1+2 indices. Precipitation is most frequently correlated with ENSO in the different regions using SOI and Niño 3.4. Using several nonparametric statistical tests, it is determined that while average precipitation received in Hawaii during El Niño events is significantly different from average precipitation (1971-2000) and from precipitation received during La Niña events, the relationship between precipitation and individual ENSO events within regions is rarely significant. Finally, during El Niño or La Nña events, average precipitation receipt across the regions co-varies during winter and summer under concurrent conditions and a one-season lag. Synoptic patterns are examined and indicate a deviation from average conditions during ENSO events that affects subsidence and precipitation patterns. Copyright © 2007 by V. H. Winston & Son, Inc. All rights reserved.
• Ray, A. J., Garfin, G. M., Wilder, M., V\'asquez-Le\'on, M., Lenart, M., & Comrie, A. C. (2007). Applications of monsoon research: Opportunities to inform decision making and reduce regional vulnerability.. Journal of Climate, 20(9), 1608-1627.
• Ray, A. J., Garfin, G. M., Wilder, M., Vásquez-León, M., Lenart, M., & Comrie, A. C. (2007). Applications of Monsoon research: Opportunities to inform decision making and reduce regional vulnerability. Journal of Climate, 20(Issue 9). doi:10.1175/jcli4098.1
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  This article presents ongoing efforts to understand interactions between the North American monsoon and society in order to develop applications for monsoon research in a highly complex, multicultural, and binational region. The North American monsoon is an annual precipitation regime that begins in early June in Mexico and progresses northward to the southwestern United States. The region includes stakeholders in large urban complexes, productive agricultural areas, and sparsely populated and and semiarid ecosystems. The political, cultural, and socioeconomic divisions between the United States and Mexico create a broad range of sensitivities to climate variability as well as capacities to use forecasts and other information to cope with climate. This paper highlights methodologies to link climate science with society and to analyze opportunities for monsoon science to benefit society in four sectors: natural hazards management, agriculture, public health, and water management. A list of stakeholder needs and a calendar of decisions is synthesized to help scientists link user needs to potential forecasts and products. To ensure usability of forecasts and other research products, iterative scientist-stakeholder interactions, through integrated assessments, are recommended. These knowledge-exchange interactions can improve the capacity for stakeholders to use forecasts thoughtfully and inform the development of research, and for the research community to obtain feedback on climate-related products and receive insights to guide research direction. It is expected that integrated assessments can capitalize on the opportunities for monsoon science to inform decision making and, in the best instances, reduce regional climate vulnerabilities and enhance regional sustainability. © 2007 American Meteorological Society.
• Tamerius, J. D., Wise, E. K., Uejio, C. K., McCoy, A. L., & Comrie, A. C. (2007). Climate and human health: Synthesizing environmental complexity and uncertainty. Stochastic Environmental Research and Risk Assessment, 21(Issue 5). doi:10.1007/s00477-007-0142-1
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  Broad relationships between weather and human health have long been recognized, and there is currently a large body of research examining the impacts of climate change on human health. Much of the literature in this area examines climate-health relationships at global or regional levels, incorporating mostly generalized responses of pathogens and vectors to broad changes in climate. Far less research has been done to understand the direct and indirect climate-mediated processes involved at finer scales. Thus, some studies simplify the role of climate and may over- or under-estimate the potential response, while others have begun to highlight the subtle and complex role for climate that is contingent on other relevant processes occurring in natural and social environments. These fundamental processes need to be understood to determine the effects of past, current and future climate variation and change on human health. We summarize the principal climate variables and climate-dependent processes that are believed to impact human health across a representative set of diseases, along with key uncertainties in these relationships. © Springer-Verlag 2007.
• Tamerius, J. D., Wise, E. K., Uejio, C. K., McCoy, A. L., & Comrie, A. C. (2007). Climate and human health: synthesizing environmental complexity and uncertainty. Stochastic Environmental Research and Risk Assessment, 21(5), 601--613.
• Comrie, A. C. (2005). Climate factors influencing coccidioidomycosis seasonality and outbreaks. Environmental Health Perspectives, 113(Issue 6). doi:10.1289/ehp.7786
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  Although broad links between climatic factors and coccidioidomycosis have been established, the identification of simple and robust relationship linking climatic controls to seasonal timing and outbreaks of the disease has remained elusive. Using an adaptive data-oriented method for estimating data of exposure, in this article I analyze hypotheses linking climate and dust to fungal growth and dispersion, and evaluate their respective roles for Pima County, Arizona. Results confirm a strong bimodal disease seasonality that was suspected but not previous seen in reported data. Dispersion-related conditions are important predictors od coccidioidomycosis incidence during fall, winter, and the arid foresummer. However, precipitation during the normally arid foresummer 1.5-2 years before the season of exposure is the dominant predictor of the disease in all seasons, accounting for half of the overall variance. Cross-validated models combining antecedent and concurrent conditions explain 80% of the variance in coccidioidomycosis incidence.
• Comrie, A. C. (2005). Climate factors influencing coccidioidomycosis seasonality and outbreaks. Environmental health perspectives, 113(6), 688.
• Park, B. J., Sigel, K., Vaz, V., Komatsu, K., McRill, C., Phelan, M., Colman, T., Comrie, A. C., Warnock, D. W., Galgiani, J. N., & Hajjeh, R. A. (2005). An epidemic of coccidioidomycosis in Arizona associated with climatic changes, 1998-2001. Journal of Infectious Diseases, 191(Issue 11). doi:10.1086/430092
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  Background. Reports of coccidioidomycosis cases in Arizona have increased substantially. We investigated factors associated with the increase. Methods. We analyzed the National Electronic Telecommunications System for Surveillance (NETSS) data from 1998 to 2001 and used Geographic Information Systems (GIS) to map high-incidence areas in Maricopa County. Poisson regression analysis was performed to assess the effect of climatic and environmental factors on the number of monthly cases; a model was developed and tested to predict outbreaks. Results. The overall incidence in 2001 was 43 cases/100,000 population, a significant (P < .01, test for trend) increase from 1998 (33 cases/100,000 population); the highest age-specific rate was in persons ≥65 years old (79 cases/100,000 population in 2001). Analysis of NETSS data by season indicated high-incidence periods during the winter (November-February). GIS analysis showed that the highest-incidence areas were in the periphery of Phoenix. Multivariable Poisson regression modeling revealed that a combination of certain climatic and environmental factors were highly correlated with seasonal outbreaks (R2 = 0.75). Conclusions. Coccidioidomycosis in Arizona has increased. Its incidence is driven by seasonal outbreaks associated with environmental and climatic changes. Our study may allow public-health officials to predict seasonal outbreaks in Arizona and to alert the public and physicians early, so that appropriate preventive measures can be implemented. © 2005 by the Infectious Diseases Society of America. All rights reserved.
• Park, B. J., Sigel, K., Vaz, V., Komatsu, K., McRill, C., Phelan, M., Colman, T., Comrie, A. C., Warnock, D. W., Galgiani, J. N., & others, . (2005). An epidemic of coccidioidomycosis in Arizona associated with climatic changes, 1998--2001. Journal of Infectious Diseases, 191(11), 1981.
• Wise, E. K., & Comrie, A. C. (2005). Extending the Kolmogorov--Zurbenko filter: application to ozone, particulate matter, and meteorological trends. Journal of the Air \& Waste Management Association, 55(8), 1208--1216.
• Wise, E. K., & Comrie, A. C. (2005). Extending the kolmogorov–zurbenko filter: Application to ozone, particulate matter, and meteorological trends. Journal of the Air and Waste Management Association, 55(Issue 8). doi:10.1080/10473289.2005.10464718
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  Tropospheric ozone (O3) and particulate matter (PM) are pollutants of great concern to air quality managers. Federal standards for these pollutants have been promulgated in recent years because of the known adverse effects of the pollutants on human health, the environment, and visibility. Local meteorological conditions exert a strong influence over day‐to‐day variations in pollutant concentrations; therefore, the meteorological signal must be removed in order for air quality planners and managers to examine underlying emissions-related trends and make better air quality management decisions for the future. Although the Kolmogorov–Zurbenko (KZ) filter has been widely used for this type of trend separation in O3 studies in the eastern United States, this article aims to extend the method in three key ways. First, whereas the KZ filter is known as a useful tool for O3 analysis, this study also evaluates its effectiveness when applied to PM. Second, the method was applied to Tucson, AZ, a city in the semi‐arid southwestern United States (Southwest), to evaluate the appropriateness of the method in a region with weaker synoptic weather controls on air quality than the eastern United States. Third, additional forms of output were developed and tailored to be more applicable to decision-makers’ needs through a partnership between academic researchers and air quality planners and managers. Results of the study indicate that the KZ filter is a useful method for examining emissions‐related PM trends, resulting in small, but potentially significant, differences after adjustment. For the Tucson situation with weaker synoptic controls, the KZ method identified mixing height as a more important variable than has been found in other cities. © 2005 Air & Waste Management Association.
• Wise, E. K., & Comrie, A. C. (2005). Meteorologically adjusted urban air quality trends in the Southwestern United States. Atmospheric Environment, 39(16), 2969--2980.
• Wise, E. K., & Comrie, A. C. (2005). Meteorologically adjusted urban air quality trends in the Southwestern United States. Atmospheric Environment, 39(Issue 16). doi:10.1016/j.atmosenv.2005.01.024
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  Cities in the Southwestern United States (Southwest) are often close to violating tropospheric ozone (ozone) and particulate matter (PM) federal air quality standards, and local climate and weather conditions play a large part in determining whether or not pollutant levels exceed the federally mandated limits and by what magnitude. The Kolmogorov-Zurbenko (KZ) filter method has been used in a number of studies in the Eastern United States to determine meteorological controls on ozone concentrations and to separate out those effects in order to examine underlying trends. The Southwest, however, experiences a different climate regime than other parts of the country, and atmospheric controls on air quality in the region have not been examined in this manner. This paper determines which meteorological variables most influence ozone and PM in the Southwest and examines patterns of underlying pollutant trends due to emissions. Ozone and PM data were analyzed over the time period 1990-2003 for the Southwest's five major metropolitan areas: Albuquerque, NM; El Paso, TX; Las Vegas, NV; Phoenix, AZ; and Tucson, AZ. Results indicate that temperature and mixing height most strongly influence ozone conditions, while moisture levels (particularly relative humidity) are the strongest predictors of PM concentrations in all five cities examined. Meteorological variability typically accounts for 40-70% of ozone variability and 20-50% of PM variability. Long-term ozone trends are highly variable, but records from most stations indicate increasing concentrations over the last decade. Long-term trends in PM concentrations were relatively flat in all five cities analyzed but contained coincident extremes unrelated to meteorology. © 2005 Elsevier Ltd. All rights reserved.
• Abraham, J. S., & Comrie, A. C. (2004). Real-time ozone mapping using a regression-interpolation hybrid approach, applied to Tucson, Arizona. Journal of the Air \& Waste Management Association, 54(8), 914--925.
• Abraham, J. S., & Comrie, A. C. (2004). Real-time ozone mapping using a regression-interpolation hybrid approach, applied to tucson, arizona. Journal of the Air and Waste Management Association, 54(Issue 8). doi:10.1080/10473289.2004.10470960
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  Real-time ozone (O3) maps, intended for public access and mass media, are generated from spatially interpolating (i.e., kriging) sparse monitoring data and are typically characterized by over-smoothed surfaces that inadequately represent local-scale spatial patterns (e.g., averaged over 1 km2). In this paper, a hybrid regression-interpolation methodology is developed to enhance the representation of local-scale spatiotemporal patterns with an application to Tucson, Arizona. The mapping of local patterns is enhanced with pre-interpolation regression modeling of local-scale deviation-from-mean variability, preserving variation in the monitor data that is ubiquitous across the modeling domain (i.e., the areal mean). The model is trained on several years of deviation-from-mean hourly O3 data, and predictor variables are developed using theoretically and empirically derived proxy regression variables. The regression model explains a significant proportion of the variation in the data (r2 = 0.54), with an average error of 7.1 ppb. When augmented with the areal mean, the r2 of the pre-interpolation model increases to 0.847. Model residuals are then spatially interpolated to the extents of the modeling domain. Final concentration estimate maps are the summation of areal mean, regression, and spatially interpolated surfaces, preserving absolute values at monitor locations. © 2004 Air & Waste Management Association.
• Brown, D. P., & Comrie, A. C. (2004). A winter precipitation 'dipole' in the western United States associated with multidecadal ENSO variability. Geophysical Research Letters, 31(Issue 9). doi:10.1029/2003gl018726
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  The variability of winter precipitation across the western United States has important implications for a wide range of physical and socioeconomic systems. While El Niño-Southern Oscillation (ENSO) teleconnections explain a high degree of interannual variance in western U.S. winter precipitation, their influence on decadal time scales is less well understood. In this study, we examine the relationship between ENSO conditions and winter precipitation in the western U.S. within the context of decadal-scale variability, as represented by phasing of the Pacific Decadal Oscillation (PDO). We identify spatial inconsistencies in the ENSO-precipitation relationship, commensurate with PDO phase shifts, which take the form of a 'dipole' signature across the western U.S. This finding has implications for the knowledge of uncertainty of ENSO teleconnections, and may prove meaningful for users of climate information throughout the region. Copyright 2004 by the American Geophysical Union.
• Brown, D. P., & Comrie, A. C. (2004). A winter precipitation ‘dipole’in the western United States associated with multidecadal ENSO variability. Geophysical Research Letters, 31(9).
• Comrie, A. C., & Kolivras, K. N. (2004). Climate and infectious disease in the southwestern United States. Progress in Physical Geography, 28, 387-398.
• Crimmins, M. A., & Comrie, A. C. (2004). Interactions between antecedent climate and wildfire variability across south-eastern Arizona. International Journal of Wildland Fire, 13(Issue 4). doi:10.1071/wf03064
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  Long-term antecedent climate conditions are often overlooked as important drivers of wildfire variability. Fuel moisture levels and fine-fuel productivity are controlled by variability in precipitation and temperature at long timescales (months to years) before wildfire events. This study examines relationships between wildfire statistics (total area burned and total number of fires) aggregated for south-eastern Arizona and antecedent climate conditions relative to 29 fire seasons (April-May-June) between 1973 and 2001. High and low elevation fires were examined separately to determine the influence of climate variability on dominant fuel types (low elevation grasslands with fine fuels v. high elevation forests with heavy fuels). Positive correlations between lagged precipitation and total area burned highlight the importance of climate in regulating fine fuel production for both high and low elevation fires. Surprisingly, no significant negative correlations between precipitation and seasonal wildfire statistics were found at any seasonal lag. Drought conditions were not associated with higher area burned or a greater number of fires. Larger low elevation fires were actually associated with wet antecedent conditions until just before the fire season. Larger high elevation fires were associated with wet conditions during seasons up to 3 years before the fire season.
• Kolivras, K. N., & Comrie, A. C. (2004). Climate and infectious disease in the southwestern United States. Progress in Physical Geography, 28(Issue 3). doi:10.1191/0309133304pp417ra
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  As in many parts of the world, climate variability has a strong impact on infectious diseases within the southwestern USA. Moisture and temperature conditions can either indirectly impact disease by providing an environment conducive to the growth of an animal host or reservoir, or directly through the survival and dispersal of an infectious agent. It is also expected that climate change will affect the number of cases and/or the spatial distribution of infectious diseases. Before the effects of climate change on diseases can be determined, an understanding of the basic relationship between incidence and climate variability should be established. A review of climate impacts on four infectious diseases (hantavirus, plague, dengue and coccidioidomycosis) currently found in southwestern USA (or potentially found in the southwest in the case of dengue) is followed by suggested future research to further understand the relationship between climate variability/change and disease. © Arnold 2004.
• Comrie, A., Diaz, H., Morehouse, B., & others, . (2003). Climate doesn't stop at the border: US-Mexico climatic regions and causes of variability.. Climate and water: transboundary challenges in the Americas, 291--316.
• Control, C., (CDC, P., & others, . (2003). Increase in coccidioidomycosis--Arizona, 1998-2001.. MMWR. Morbidity and mortality weekly report, 52(6), 109.
• Kolivras, K. N., & Comrie, A. C. (2003). Modeling valley fever (coccidioidomycosis) incidence on the basis of climate conditions. International Journal of Biometeorology, 47(Issue 2). doi:10.1007/s00484-002-0155-x
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  Valley fever (coccidioidomycosis) is a disease endemic to arid regions within the Western Hemisphere, and is caused by a soil-dwelling fungus, Coccidioides immitis. Incidence data for Pima County, reported to the Arizona Department of Health Services as new cases of valley fever, were used to conduct exploratory analyses and develop monthly multivariate models of relationships between valley fever incidence and climate conditions and variability in Pima County, Arizona, USA. Bivariate and compositing analyses conducted during the exploratory portion of the study revealed that antecedent temperature and precipitation in different seasons are important predictors of incidence. These results were used in the selection of candidate variables for multivariate predictive modeling, which was designed to predict deviation from mean incidence on the basis of past, current, and forecast climate conditions. The models were specified using a backward stepwise procedure, and were most sensitive to key predictor variables in the winter season and variables that were time-lagged 1 year or more prior to the month being predicted. Model accuracy was generally moderate (r2 values for the monthly models, tested on independent data, ranged from 0.15 to 0.50), and months with high incidence can be predicted more accurately than months with low incidence.
• Kolivras, K. N., & Comrie, A. C. (2003). Modeling valley fever (coccidioidomycosis) incidence on the basis of climate conditions. International journal of biometeorology, 47(2), 87--101.
• Brown, D. P., & Comrie, A. C. (2002). Spatial modeling of winter temperature and precipitation in Arizona and New Mexico, USA. Climate Research, 22(2), 115--128.
• Brown, D. P., & Comrie, A. C. (2002). Spatial modeling of winter temperature and precipitation in Arizona and New Mexico, USA. Climate Research, 22(Issue 2). doi:10.3354/cr022115
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  The development of a statistical modeling technique suitable for producing mean and interannual gridded climate datasets for a topographically varying domain is undertaken. Stepwise regression models at 1 x 1 km resolution are generated to estimate mean winter temperature and precipitation for the Southwest United States for the years 1961-1990. Topographic predictor variables are used to explain spatial variance in the datasets. Kriging and inverse distance weighting interpolation algorithms are utilized to account for model residuals. The final regression models show a high degree of explained variance for temperature (R2 = 0.98, mean bias error [MBE] = -0.15°C, root-mean-squared error [RMSE] = 0.74°C) and a moderate degree of explained variance for precipitation (R2 = 0.63, MBE = -1.4 mm, RMSE = 27.0 mm). Several smaller-scale precipitation regression models are developed for comparison to the domain-wide model, but do not show marked accuracy improvements. Observed values of winter temperature and precipitation from the years 1961-1999 are compared to the 30 yr modeled means, and the differences are interpolated using kriging (temperature) and inverse distance weighting (precipitation). The result is a 39 yr time series of maps and datasets of winter temperature and precipitation at 1 x 1 km resolution for the Southwest United States.
• Brown, D. P., & Comrie, A. C. (2002). Sub-regional seasonal precipitation linkages to SOI and PDO in the Southwest United States. Atmospheric Science Letters, 3(2-4), 94--102.
• Brown, D. P., & Comrie, A. C. (2002). Sub-regional seasonal precipitation linkages to SOI and PDO in the Southwest United States. Atmospheric Science Letters, 3(Issue 2-4). doi:10.1006/asle.2002.0057
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  This paper highlights the relationship between precipitation variability at the sub-regional level in the Southwest United States and the SOI and PDO climate teleconnection indices during the period 1950-2000. Statistical correlations at α = 0.05 and 0.01 levels are calculated for fall, winter, and spring precipitation in the Southwest, and contemporaneous and antecedent seasonal SOI and PDO index values. A strong SOI-winter precipitation signal is seen to progress across Arizona and New Mexico from southwest to northeast over a three-season lagged period. The PDO also exhibits a strong relationship with winter and spring precipitation in New Mexico; however, the PDO is not well correlated with precipitation in Arizona. The results underscore the non-uniform spatio-temporal relationships of the SOI and PDO indices as they relate to the precipitation regime of the Southwest, and provide a framework for future diagnostic analyses of these relationships. © 2002 Royal Meteorological Society.
• Cavazos, T., Comrie, A. C., & Liverman, D. M. (2002). Intraseasonal variability associated with wet monsoons in southeast Arizona. Journal of Climate, 15(Issue 17). doi:10.1175/1520-0442(2002)015<2477:ivawwm>2.0.co;2
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  The intraseasonal evolution of the North American monsoon in southeast Arizona during the 1980-93 period is investigated using a neural network-based nonlinear classification technique known as the self-organizing map (SOM). The goal of the SOM algorithm is to discover meaningful low-dimensional structures hidden in the high-dimensional observations. Various daily lagged atmospheric fields (850-hPa meridional winds. 700-hPa specific humidity, 500-hPa geopotential heights, and 850-500-hPa thickness) for the summer season (June-July-August-September) of the 1980-93 period are used in the nonlinear classification of monsoon modes. Special emphasis is given to the wettest monsoon modes. The neural network classification successfully captures the multidimensional interaction of the atmospheric variables during the monsoon evolution, and shows monsoon "bursts" and "breaks" in a given year. Spectral analysis of daily summer rainfall in the study area reveals a significant peak in the 12-18-day band; a secondary and significant peak is also found near 40 days. Thus, monsoon bursts and breaks seem to be modulated by low-frequency variability. The SOM nonlinear classification shows that the mature phase of the monsoon is associated with two distinct intraseasonal (> 10 days) wet monsoon modes. The signature of the wettest monsoon mode is a zonal three-cell anomalous midtropospheric height pattern over the North Pacific-North American sector, suggesting a large-scale dynamical mechanism, possibly linked to sea surface temperature (SST) anomalies in the North Pacific. This zonal mode, which is most frequent in July and August, is characterized by an enhanced and northeastward-displaced monsoon ridge, large amounts of midtropospheric moisture over the study area, and an out of phase relationship between precipitation in the southwest United States and precipitation in the Great Plains. The zonal mode has been recognized in longer datasets and it is the most typical mode that characterizes the mature phase of the monsoon in the southwest United States. In contrast, the second wettest intraseasonal monsoon mode does not show a monsoon ridge, but a meridional three-cell anomalous midtropospheric height pattern along the west coast of North America, weak height anomalies over the rest of North America, and large amounts of moisture over the study area. Importantly, this meridional mode, which is most frequent in August and September, does not show out of phase links to Great Plains precipitation. The meridional wet mode also shows an anomalous low-level cyclonic circulation off the west coast of central-south Mexico suggesting that convective activity off the southern Mexican coast-possibly associated with the intertropical convergence zone-may cross over the Isthmus of Tehuantepec toward the Gulf of Mexico and the southern United States. This would explain the weak link between precipitation in the Southwest and precipitation in the Great Plains during August and September of the 1980-93 period. At more regional scales, the zonal wet mode is also characterized by a latitudinal gradient of SST anomalies between Baja California and southern Mexico and reversed low-level flow over the Gulf of California. Looking at extreme wet monsoons outside of the study period (e.g., 1955, 1959, 1999) it is shown that the positive SST anomaly pattern along the Pacific coast of Baja California, which characterized wet events during 1980-93, can be completely reversed during other extreme wet events. These contrasting results suggest that interaction between local and remote forcing mechanisms over the study area are complex during extreme events and needs further investigation.
• Cavazos, T., Comrie, A. C., & Liverman, D. M. (2002). Intraseasonal variability associated with wet monsoons in southeast Arizona.. Journal of Climate, 15(17).
• Comrie, A. C., & Broyles, B. (2002). Variability and spatial modeling of fine-scale precipitation data for the Sonoran Desert of south-west Arizona. Journal of Arid Environments, 50(4), 573--592.
• Comrie, A. C., & Broyles, B. (2002). Variability and spatial modeling of fine-scale precipitation data for the Sonoran Desert of south-west Arizona. Journal of Arid Environments, 50(Issue 4). doi:10.1006/jare.2001.0866
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  We present a unique new set of high spatial resolution precipitation data from a storage gauge network, for the sparsely observed northern Sonoran desert in south-west Arizona. We examine the nature and causes of the highly complex seasonal and spatial variability in the data, using fine-scale maps developed via spatial modeling and interpolation. These high-resolution maps had explained variances approaching 1.00, and precipitation errors of about 1% in winter and about 10% in summer. Seasonal precipitation ranges from near zero to almost 15 in across the area, and shows high interannual variability. Localized convectional processes lead to summer anomalies that are more spatially complex than in winter when broad-scale synoptic and frontal processes cause precipitation. In general, summer and winter precipitation variability are tied to meridional-zonal shifts and east-west movement of the respective anticyclone or trough pattern over the region. Statistical links between major weather stations in the region and precipitation across the area are spatially inconsistent, especially in the west. © 2002 Elsevier Science Ltd.
• Diem, J. E., & Comrie, A. C. (2002). Predictive mapping of air pollution involving sparse spatial observations. Environmental Pollution, 119(Issue 1). doi:10.1016/s0269-7491(01)00308-6
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  A limited number of sample points greatly reduces the availability of appropriate spatial interpolation methods. This is a common problem when one attempts to accurately predict air pollution levels across a metropolitan area. Using ground-level ozone concentrations in the Tucson, Arizona, region as an example, this paper discusses the above problem and its solution, which involves the use of linear regression. A large range of temporal variability is used to compensate for sparse spatial observations (i.e. few ozone monitors). Gridded estimates of emissions of ozone precursor chemicals, which are developed, stored, and manipulated within a geographic information system, are the core predictor variables in multiple linear regression models. Cross-validation of the pooled models reveals an overall R2 of 0.90 and approximately 7% error. Composite ozone maps predict that the highest ozone concentrations occur in a monitor-less area on the eastern edge of Tucson. The maps also reveal the need for ozone monitors in industrialized areas and in rural, forested areas. Copyright © 2002 Elsevier Science Ltd.
• Diem, J. E., & Comrie, A. C. (2002). Predictive mapping of air pollution involving sparse spatial observations. Environmental pollution, 119(1), 99--117.
• Ni, F., Cavazos, T., Hughes, M. K., Comrie, A. C., & Funkhouser, G. (2002). Cool-season precipitation in the southwestern USA since AD 1000: Comparison of linear and nonlinear techniques for reconstruction. International Journal of Climatology, 22(Issue 13). doi:10.1002/joc.804
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  A 1000 year reconstruction of cool-season (November-April) precipitation was developed for each climate division in Arizona and New Mexico from a network of 19 tree-ring chronologies in the southwestern USA. Linear regression (LR) and artificial neural network (NN) models were used to identify the cool-season precipitation signal in tree rings. Using 1931-88 records, the stepwise LR model was cross-validated with a leave-one-out procedure and the NN was validated with a bootstrap technique. The final models were also independently validated using the 1896-1930 precipitation data. In most of the climate divisions, both techniques can successfully reconstruct dry and normal years, and the NN seems to capture large precipitation events and more variability better than the LR. In the 1000 year reconstructions the NN also produces more distinctive wet events and more variability, whereas the LR produces more distinctive dry events. The 1000 year reconstructed precipitation from the two models shows several sustained dry and wet periods comparable to the 1950s drought (e.g. 16th century mega drought) and to the post-1976 wet period (e.g. 1330s, 1610s). The impact of extreme periods on the environment may be stronger during sudden reversals from dry to wet, which were not uncommon throughout the millennium, such as the 1610s wet interval that followed the 16th century mega drought. The instrumental records suggest that strong dry to wet precipitation reversals in the past 1000 years might be linked to strong shifts from cold to warm El Niño-southern oscillation events and from a negative to positive Pacific decadal oscillation. © 2002 Royal Meteorological Society.
• Ni, F., Cavazos, T., Hughes, M. K., Comrie, A. C., & Funkhouser, G. (2002). Cool-season precipitation in the southwestern USA since AD 1000: comparison of linear and nonlinear techniques for reconstruction. International Journal of Climatology, 22(13), 1645--1662.
• Sheppard, P. R., Comrie, A. C., Packin, G. D., Angersbach, K., & Hughes, M. K. (2002). The climate of the US Southwest. Climate Research, 21(3), 219--238.
• Sheppard, P. R., Comrie, A. C., Packin, G. D., Angersbach, K., & Hughes, M. K. (2002). The climate of the US Southwest. Climate Research, 21(Issue 3). doi:10.3354/cr021219
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  This paper summarizes the current state of knowledge of the climate of southwest USA (the 'Southwest'). Low annual precipitation, clear skies, and year-round warm climate over much of the Southwest are due in large part to a quasi-permanent subtropical high-pressure ridge over the region. However, the Southwest is located between the mid-latitude and subtropical atmospheric circulation regimes, and this positioning relative to shifts in these regimes is the fundamental reason for the region's climatic variability. Furthermore, the Southwest's complex topography and its geographical proximity to the Pacific Ocean, the Gulf of California, and the Gulf of Mexico also contribute to this region's high climatic variability. El Niño, which is an increase in sea-surface temperature of the eastern equatorial Pacific Ocean with an associated shift of the active center of atmospheric convection from the western to the central equatorial Pacific, has a well-developed teleconnection with the Southwest, usually resulting in wet winters. La Niña, the opposite oceanic case of El Niño usually results in dry winters for the Southwest. Another important oceanic influence on winter climate of the Southwest is a feature called the Pacific Decadal Oscillation (PDO), which has been defined as temporal variation in sea-surface temperatures for most of the Northern Pacific Ocean. The effects of ENSO and PDO can amplify each other, resulting in increased annual variability in precipitation over the Southwest. The major feature that sets the climate of the Southwest apart from the rest of the United States is the North American monsoon, which in the US is most noticeable in Arizona and New Mexico. Up to 50% of the annual rainfall of Arizona and New Mexico occurs as monsoonal storms from July through September. Instrumental measurement of temperature and precipitation in the Southwest dates back to the middle to late 1800s. From that record, average annual rainfall of Arizona is 322 mm (12.7″), while that of New Mexico is 340 mm (13.4″), and mean annual temperature of New Mexico is cooler (12°C [53°F] than Arizona (17°C [62°F]). As instrumental meteorological records extend back only about 100 to 120 yr throughout the Southwest, they are of limited utility for studying climate phenomena of long time frames. Hence, there is a need to extend the measured meteorological record further back in time using so-called 'natural archive' paleoclimate records. Tree-ring data, which provide annual resolution, range throughout the Southwest, extend back in time for up to 1000 yr or more in various forests of the Southwest, and integrate well the influences of both temperature and precipitation, are useful for this assessment of climate of the Southwest. Tree growth of mid-elevation forests typically responds to moisture availability during the growing season, and a commonly used climate variable in paleo-precipitation studies is the Palmer Drought Severity Index (PDSI), which is a single variable derived from variation in precipitation and temperature. June-August PDSI strongly represents precipitation and, to a lesser extent, temperature of the year prior to the growing season (prior September through current August). The maximum intra-ring density of higher elevation trees can yield a useful record of summer temperature variation. The combined paleo-modern climate record has at least 3 occurences of multi-decadal variation (50 to 80 yr) of alternating dry (below average PDSI) to wet (above average PDSI). The amplitude of this variation has increased since the 1700s. The most obvious feature of the temperature record is its current increase to an extent unprecedented in the last 400 yr. Because this warming trend is outside the variation of the natural archives, it is possible that anthropogenic impacts, such as increased atmospheric concentrations of greenhouse trace gases, are playing a role in climate of the Southwest. Accordingly, this pattern merits further research in search of its cause or combination of causes.
• Diem, J. E., & Comrie, A. C. (2001). Air Quality, Climate, and Policy: A Case Study of Ozone Pollution in Tucson, Arizona. Professional Geographer, 53(Issue 4). doi:10.1111/0033-0124.00298
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  This article addresses the need to better understand the complex interactions between climate, human activities, vegetation responses, and surface ozone so that more informed air-quality policy recommendations can be made. The impacts of intraseasonal climate variations on ozone levels in Tucson, Arizona from April through September of 1995 to 1998 are determined by relating variations in ozone levels to variations in atmospheric conditions and emissions of ozone's precursor chemicals, volatile organic compounds (VOCs) and nitrogen oxides (NOx), and by determining month-specific atmospheric conditions that are conducive to elevated ozone levels. Results show that the transport of ozone and its precursor chemicals within the Tucson area causes the highest ozone levels to be measured at a downwind monitor. The highest ozone levels occur in August, due in part to the presence of the North American monsoon. Atmospheric conditions conducive to elevated ozone concentrations differ substantially between the arid foresummer (May and June) and the core monsoon months (July and August). Transport of pollution from Phoenix may have a substantial impact on elevated ozone concentrations during April, May, and June, while El Paso/Ciudad Juarez –derived pollution may contribute significantly to elevated ozone concentrations in August and September. Two broad policy implications derive from this work. Regional pollutant transport, both within the U.S. and between the U.S. and Mexico, is a potential issue that needs to be examined more intensively in future studies. In addition, spatiotemporal variations in sensitivities of ozone production require the adoption of both NOx and VOC control measures to reduce ozone levels in the Tucson area. © 2001 Taylor & Francis Group, LLC. All rights reserved.
• Diem, J. E., & Comrie, A. C. (2001). Air quality, climate, and policy: a case study of ozone pollution in Tucson, Arizona. The Professional Geographer, 53(4), 469--491.
• Diem, J. E., & Comrie, A. C. (2001). Allocating anthropogenic pollutant emissions over space: Application to ozone pollution management. Journal of Environmental Management, 63(Issue 4). doi:10.1006/jema.2001.0492
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  An inventory of volatile organic compound (VOC) and nitrogen oxides (NOx) emissions is an important tool for the management of ground-level ozone pollution. This paper has two broad aims: it illustrates the potential of a geographic information system (GIS) for enhancing an existing spatially-aggregated, anthropogenic emissions inventory (EI) for Tucson, AZ, and it discusses the ozone-specific management implications of the resulting spatially-disaggregated El. The main GIS-related methods include calculating emissions for specific features, spatially disaggregating region-wide emissions totals for area sources, and adding emissions from various point sources. In addition, temporal allocation factors enable the addition of a multi-temporal component to the inventory. The resulting inventory reveals that on-road motor vehicles account for approximately 50% of VOC and NOx emissions annually. On-road motor vehicles and residential wood combustion are the largest VOC sources in the summer and winter months, respectively. On-road motor vehicles are always the largest NOx sources. The most noticeable weekday vs. weekend VOC emissions differences are triggered by increased residential wood combustion and increased lawn and garden equipment use on weekends. Concerning the El's uncertainties and errors, on-road mobile, construction equipment, and lawn and garden equipment are identified as sources in the most need of further investigation. Overall, the Els spatial component increases its utility as a management tool, which might involve visualization-driven analyses and air quality modeling. © 2001 Academic Press.
• Diem, J. E., & Comrie, A. C. (2001). Allocating anthropogenic pollutant emissions over space: application to ozone pollution management. Journal of environmental management, 63(4), 425--447.
• Kolivras, K. N., Johnson, P. S., Comrie, A. C., & Yool, S. R. (2001). Environmental variability and coccidioidomycosis (valley fever). Aerobiologia, 17(1), 31--42.
• Wright, W. E., Long, A., Comrie, A. C., Leavitt, S. W., Cavazos, T., & Eastoe, C. (2001). Monsoonal moisture sources revealed using temperature, precipitation, and precipitation stable isotope timeseries. Geophysical Research Letters, 28(Issue 5). doi:10.1029/2000gl012094
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  Results of analyses using timeseries of mean temperature, precipitation amount, and stable isotopes from precipitation from July-August in Tucson, Arizona, have revealed atmospheric circulation patterns related to the North American Monsoon in the U.S. Southwest. The isotope timeseries and Tucson air temperatures and precipitation amount are significantly correlated. The temperature and isotope timeseries also correlate significantly with regional and extra-regional specific humidity, and with Eastern Pacific SSTs near the Mexican coast, evidence for a dominantly Pacific/Gulf of California summer moisture source for the period 1983-1999. Separation of extra-regional wind vector datasets into groups of years matching relative isotopic depletion or enrichment of the Tucson July-August precipitation seasonal means for the stable isotope timeseries (usually the extreme years in the Tucson seasonal temperature means) suggest circulation patterns entraining more tropical moisture in cooler/isotopically depleted years, and entraining less tropical moisture in hotter/isotopically enriched years.
• Wright, W. E., Long, A., Comrie, A., Leavitt, S., Cavazos, T., & Eastoe, C. (2001). Monsoonal moisture sources revealed using temperature, precipitation, and precipitation stable isotope timeseries. Geophysical Research Letters, 28(5), 787--790.
• Yarnal, B., Comrie, A. C., Frakes, B., & Brown, D. P. (2001). Developments and prospects in synoptic climatology. International Journal of Climatology, 21(15), 1923--1950.
• Yarnal, B., Comrie, A. C., Frakes, B., & Brown, D. P. (2001). Developments and prospects in synoptic climatology. International Journal of Climatology, 21(Issue 15). doi:10.1002/joc.675
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  Developments in synoptic climatology in the 1990s included advances in traditional synoptic climatology, empirical downscaling, and dynamical downscaling (i.e. regional climate modelling). The research emphasis in traditional, empirical-statistical approaches to synoptic climatology shifted from methodological development to applications of widely accepted classification techniques, including manual, correlation-based, eigenvector-based, compositing and indexing schemes. In contrast, most efforts in empirical downscaling, which became a well-established field of synoptic climatology during the 1990s, were directed to model development; applications were of secondary concern. Similarly, regional climate models (RCMs) burst onto the scene during the decade and focused on model development, although important progress was made in linking or coupling RCMs to regional or local surface climate systems. This paper discusses prospects for the future of traditional synoptic climatology, empirical downscaling and regional climate modelling. It concludes by looking at the present role of geographic information system (GIS) concepts in synoptic climatology and the potential future role of GIS to the field. Copyright © 2001 Royal Meteorological Society.
• Comrie, A. C. (2000). Mapping a wind-modified Urban Heat Island in Tucson, Arizona (with comments on integrating research and undergraduate learning). Bulletin of the American Meteorological Society, 81(Issue 10). doi:10.1175/1520-0477(2000)081<2417:mawmuh>2.3.co;2
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  Tucson, Arizona, is an example of the many cities in the southwestern United States experiencing rapid growth and urban sprawl over the last several decades. The accompanying extensive modification of land use and land cover leads to many environmental impacts, including urban heat islands. The primary aim of this paper is to expand knowledge of the phenomenon for Tucson, by quantifying the amount of urban warming, and by mapping temperature patterns over the city and examining related aspects of the local-scale atmospheric circulation. The secondary aim is to document how an applied empirical research project was integrated into an introductory undergraduate climatology class via active learning. The paper begins and concludes with general and practical comments on combining the research and educational aspects of the project. An analysis of 30-yr temporal trends in urban and nonurban minimum temperatures across the region shows the rate of urban warming to be about three-quarters of the general regional warming. Tucson's urban heat island is ∼3°C over the last century, with >2°C of this warming in the last 30 years. The annual average urban warming trend over the last three decades is 0.071°C yr-1 with the strongest effect in March and the weakest effect in November. There is evidence that the latter is caused by strong, near-surface winds under stable conditions. A case study is presented comprising field measurements and map analysis of urban temperatures and supporting variables for 13 February 1999. Measurements include comprehensive mapping using vehicle-mounted thermistors and numerous local meteorological observations from around the city. Wind speeds during the field measurements were somewhat stronger than is typical of heat island studies, up to 12m s-1. Nonetheless, because of terrain-induced flows and land surface heterogeneity, complex temperature patterns were observed. Several transient katabatic flows off surrounding mountain ranges were detected, leading to localized cold pockets. Locally warm areas in other parts of the city are associated with terrain sheltering or local land surface heating. The central city showed a possible urban heating pattern with temperatures ∼2°C higher than upwind rural air.
• Comrie, A. C. (2000). Mapping a wind-modified urban heat island in Tucson, Arizona (with comments on integrating research and undergraduate learning). Bulletin of the American Meteorological Society, 81(10), 2417--2431.
• Diem, J. E., & Comrie, A. C. (2000). Integrating remote sensing and local vegetation information for a high-resolution biogenic emissions inventory— application to an urbanized, semiarid region. Journal of the Air and Waste Management Association, 50(Issue 11). doi:10.1080/10473289.2000.10464223
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  This paper presents a methodology for the development of a high-resolution (30-m), standardized biogenic volatile organic compound (BVOC) emissions inventory and a subsequent application of the methodology to Tucson, AZ. The region's heterogeneous vegetation cover cannot be modeled accurately with low-resolution (e.g., 1-km) land cover and vegetation information. Instead, local vegetation data are used in conjunction with multispectral satellite data to generate a detailed vegetation-based land-cover database of the region. A high-resolution emissions inventory is assembled by associating the vegetation data with appropriate emissions factors. The inventory reveals a substantial variation in BVOC emissions across the region, resulting from the region's diversity of both native and exotic vegetation. The importance of BVOC emissions from forest lands, desert lands, and the urban forest changes according to regional, metropolitan, and urban scales. Within the entire Tucson region, the average isoprene, monoterpene. © 2000 Air and Waste Management Association.
• Diem, J. E., & Comrie, A. C. (2000). Integrating remote sensing and local vegetation information for a high-resolution biogenic emissions inventory—application to an urbanized, semiarid region. Journal of the Air \& Waste Management Association, 50(11), 1968--1979.
• Comrie, A. C., & Diem, J. E. (1999). Climatology and forecast modeling of ambient carbon monoxide in Phoenix, Arizona. Atmospheric Environment, 33(30), 5023--5036.
• Comrie, A. C., & Diem, J. E. (1999). Climatology and forecast modeling of ambient carbon monoxide in Phoenix, Arizona. Atmospheric Environment, 33(Issue 30). doi:10.1016/s1352-2310(99)00314-3
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  We perform a climatology of factors influencing ambient carbon monoxide (CO), in which we examine the relationships between meteorology, traffic patterns, and CO at seasonal, weekly, and diurnal time scales in Phoenix, Arizona. From this analysis we identify a range of potentially important variables for statistical CO modeling. Using stepwise multivariate regression, we create a suite of models for hourly and 8-h ambient CO designed for daily operational forecasting purposes. The resulting models include variables and interaction terms related to anticipated nocturnal atmospheric stability as well as antecedent and climatological CO behavior. The models are evaluated using a range of error statistics and skill measures. The most successful approach employs a two-stage modeling strategy in which an initial prediction is made that may, depending on the forecast value, be followed by a second prediction that improves upon the first. The best models provide accurate daily forecasts of CO, with explained variances approaching 0.9 and errors under 1 ppm.
• Comrie, A., & Glenn, E. (1999). Principal components-based regionalization of precipitation regimes across the southwest United States and northern Mexico, with an application to monsoon precipitation variability. Climate Research, 10(3). doi:10.3354/cr010201
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  We determine precipitation regions for the United States-Mexico border region based on seasonality and variability of monthly precipitation at 309 stations for the period 1961 to 1990. Using a correlation matrix of input data to avoid the effect of elevation on precipitation, we apply principal components analysis with oblique rotation to regionalize this large, climatologically complex study area. We examine the applicability of the method, 2 techniques for defining region boundaries, the various defined regions themselves, and the effects of transforming input data and changing obliquity of component rotation. We obtain 9 consistent and largely contiguous regions from each of the analyses, including regions for the North American monsoon, the low deserts, the California Mediterranean regime, and for summer precipitation regimes adjoining the Gulf of Mexico. The derived regions and associated boundaries make physical sense in terms of the driving atmospheric processes, and they are robust to transformed input data and changes in rotation procedures. The central border regions are remarkably consistent across analyses, with small changes to peripheral regions. We also identify 4 monsoon sub-regions, and we illustrate the applicability of the regionalization via an analysis of relationships between monsoon precipitation variability and 500 mb pressure heights. Significantly different 500 mb circulation patterns are associated with wet and dry monsoon seasons in each of the sub-regions, and it appears that shifts in 500 mb circulation relative to the geographic position of each sub-region influence seasonal precipitation variability, directly or indirectly. There are important differences between some sub-regions, but in general wet monsoons are associated with northward meridional bulging of the subtropical anticyclone over the continental monsoon areas, while dry monsoons are associated with zonal stretching of the subtropical anticyclone over adjacent oceans with slightly higher pressure-heights. Overall, the study provides a clear regionalization of the precipitation climatology for the southwest United States and northern Mexico, and shows its utility for studies of climate variability.
• Comrie, A. C. (1998). Mapping the Climatology of Ozone Potential for the US-Mexico Border Region. Journal of the Arizona-Nevada Academy of Science, 1--12.
• Comrie, A. C., & Glenn, E. C. (1998). Principal components-based regionalization of precipitation regimes across the southwest United States and northern Mexico, with an application to monsoon precipitation variability. Climate Research, 10(3), 201--215.
• Diem, J. E., & Comrie, A. C. (1998). Estimating biogenic emissions for urban airshed modeling in Tucson, Arizona. PROC A WASTE MANAGE ASSOC ANNU MEET EXHIB, 6.
• Adams, D. K., & Comrie, A. C. (1997). The North American Monsoon. Bulletin of the American Meteorological Society, 78(Issue 10). doi:10.1175/1520-0477(1997)078<2197:tnam>2.0.co;2
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  The North American monsoon is an important feature of the atmospheric circulation over the continent, with a research literature that dates back almost 100 years. The authors review the wide range of past and current research dealing with the meteorological and climatological aspects of the North American monsoon, highlighting historical development and major research themes. The domain of the North American monsoon is large, extending over much of the western United States from its region of greatest influence in northwestern Mexico. Regarding the debate over moisture source regions and water vapor advection into southwestern North America, there is general agreement that the bulk of monsoon moisture is advected at low levels from the eastern tropical Pacific Ocean and the Gulf of California, while the Gulf of Mexico may contribute some upper-level moisture (although mixing occurs over the Sierra Madre Occidental). Surges of low-level moisture from the Gulf of California are a significant part of intraseasonal monsoon variability, and they are associated with the configuration of upper-level midlatitude troughs and tropical easterly waves at the synoptic scale, as well as the presence of low-level jets, a thermal low, and associated dynamics (including the important effects of local topography) at the mesoscale. Seasonally, the gulf surges and the latitudinal position of the midtropospheric subtropical ridge over southwestern North America appear to be responsible for much spatial and temporal variability in precipitation. Interannual variability of the North American monsoon system is high, but it is not strongly linked to El Niño or other common sources of interannual circulation variability. Recent mesoscale field measurements gathered during the South-West Area Monsoon Project have highlighted the complex nature of the monsoon-related severe storm environment and associated difficulties in modeling and forecasting.
• Adams, D. K., & Comrie, A. C. (1997). The north American monsoon. Bulletin of the American Meteorological Society, 78(10), 2197--2213.
• Comrie, A. C. (1997). Comparing Neural Networks and Regression Models for Ozone Forecasting. Journal of the Air and Waste Management Association, 47(Issue 6). doi:10.1080/10473289.1997.10463925
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  Many large metropolitan areas experience elevated concentrations of ground-level ozone pollution during the summertime “smog season”. Local environmental or health agencies often need to make daily air pollution forecasts for public advisories and for input into decisions regarding abatement measures and air quality management. Such forecasts are usually based on statistical relationships between weather conditions and ambient air pollution concentrations. Multivariate linear regression models have been widely used for this purpose, and well-specified regressions can provide reasonable results. However, pollution-weather relationships are typically complex and nonlinear—especially for ozone—properties that might be better captured by neural networks. This study investigates the potential for using neural networks to forecast ozone pollution, as compared to traditional regression models. Multiple regression models and neural networks are examined for a range of cities under different climate and ozone regimes, enabling a comparative study of the two approaches. Model comparison statistics indicate that neural network techniques are somewhat (but not dramatically) better than regression models for daily ozone prediction, and that all types of models are sensitive to different weather-ozone regimes and the role of persistence in aiding predictions. © 1997 Air & Waste Management Association.
• Comrie, A. C. (1997). Comparing neural networks and regression models for ozone forecasting. Journal of the Air \& Waste Management Association, 47(6), 653--663.
• Comrie, A. C. (1996). An all-season synoptic climatology of air pollution in the US-Mexico border region. The Professional Geographer, 48(3), 237--251.
• Comrie, A. C. (1996). An all-season synoptic climatology of air pollution in the u.s.-mexico border region. Professional Geographer, 48(Issue 3). doi:10.1111/j.0033-0124.1996.00237.x
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  The potential exists for widespread air quality problems in the U.S.-Mexico borderlands. Climate and weather are major factors governing the behavior of air pollution, and thus there is a need for greater understanding of border-region air pollution climatology. This paper presents a synoptic climatology of the 850 mb atmospheric circulation for the U.S.-Mexico border region, and an accompanying analysis of relationships between synoptic conditions and ground-level ozone. The synoptic methodology employs high-pass filtering to enable comparisons of all seasons, and it uses modified multiple k means clustering to identify six characteristic circulation patterns. The climatology succinctly summarizes important spatial and temporal complexities of border region circulation, including various pressure configurations, the seasonality of those patterns, and associated weather conditions across the region. These results are linked with ozone data for four border-region cities, and the subsequent findings highlight systematic seasonal and region-wide variations in ozone pollution corresponding to patterns of controlling climatic factors. Three high-ozone scenarios are identified, each of which selectively affects a different area or time of year. © 1996 Taylor & Francis Group, LLC. All rights reserved.
• Comrie, A. C. (1994). A synoptic climatology of rural ozone pollution at three forest sites in Pennsylvania. Atmospheric Environment, 28(9), 1601--1614.
• Comrie, A. C. (1994). A synoptic climatology of rural ozone pollution at three forest sites in Pennsylvania. Atmospheric Environment, 28(Issue 9). doi:10.1016/1352-2310(94)90306-9
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  An analysis reveals strong relationships between ozone (O3) concentratins at three rural forest sites in north-central Pennsylvania and the synoptic-scale atmospheric circulation. To identify these associations, a synoptic classification scheme is applied to daily maximum 1-h ambient surface O3 measurements for the growing seasons of 1988, 1989 and 1990. The results cover five aspects of the atmospheric circulation-rural O3 relationship: overall conditions, O3 extremes, key weather sequences, the seasonal cycle and interannual differences. Overall, high rural O3 concentrations occur with southwesterly transport conditions on the western sides of anticyclones, while low values are found in post-frontal and cyclonic conditions. While slow-moving or stagnant anticyclones are occasionally associated with high-O3 episodes, these situations are most frequent in the same southwesterly transport regime. This behavior is the inverse of that found in Pittsburgh in a closely related study by Comrie and Yarnal (Atmospheric Environment, 26B, No. 3, pp. 301-312, 1992). Unlike urban environments where air mass stagnation leads to an episode, an episode in a non-urban environment requires transport of a polluted air mass from a source region. In this latter scenario, forest O3 levels are critically dependent on the air mass history and trajectory. Key weather pattern sequences show that the southwesterly transport must be preceded by stagnation of the air mass over an upwind polluted region, with stagnation and transport each lasting 1-2 d. The relative importance of these complementary mechanisms in the O3 climatology remains the same through the growing season. The unusually hot and dry conditions of the summer 1988 were more favorable for O3 formation across all synoptic patterns, as compared to 1989 and 1990. © 1994.
• Comrie, A. C. (1994). Tracking Ozone: Air-Mass Trajectories and Pollutant Source Regions Influencing Ozone in Pennsylvania Forests. Annals of the Association of American Geographers, 84(4), 635--651.
• Comrie, A. C. (1994). Tracking Ozone: Air-Mass Trajectories and Pollutant Source Regions Influencing Ozone in Pennsylvania Forests. Annals of the Association of American Geographers, 84(Issue 4). doi:10.1111/j.1467-8306.1994.tb01880.x
• Comrie, A. C. (1992). A procedure for removing the synoptic climate signal from environmental data. International Journal of Climatology, 12(Issue 2). doi:10.1002/joc.3370120206
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  Using weather‐type frequencies from a synoptic climatology, a technique is presented that discriminates between within‐type and between‐type variations in a time series of climate‐related environmental data. The removal of the synoptic climate signal, or declimatizing, is based on normalizing the data by the mean annual weather‐type frequencies for the study period. Declimatizing is illustrated symbolically and with a worked hypothetical example. An application of the procedure to visibility data from Pittsburgh, Pennsylvania demonstrates its utility in decomposing complex climate‐related environmental data into its component synoptic and non‐synoptic influences. The methodology can also distinguish the relative importance of between‐type and within‐type changes in a synoptic climatology. Copyright © 1992 John Wiley & Sons, Ltd
• Comrie, A. C. (1992). A procedure for removing the synoptic climate signal from environmental data. International journal of climatology, 12(2), 177--183.
• Comrie, A. C. (1992). An enhanced synoptic climatology of ozone using a sequencing technique. Physical Geography, 13(1), 53--65.
• Comrie, A. C. (1992). An enhanced synoptic climatology of ozone using a sequencing technique. Physical Geography, 13(Issue 1). doi:10.1080/02723646.1992.10642444
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  A synoptic classification scheme is derived to examine basic associations between surface ozone pollution and the atmospheric circulation. Nine weather types are related to the daily maximum ozone concentration in Pittsburgh, Pennsylvania, for the years 1978–1987. A sequencing technique is developed to extract the maximum utility from the classification scheme. An analysis of the sequences of synoptic weather types highlights additional spatial and temporal information, such as air mass origins, system speed, and seasonal variations. Low concentrations of ozone are experienced in winter during lake-effect and cyclonic storms, which move in rapidly from the north-west, bringing cold, cloudy, windy conditions with precipitation. High concentrations occur during summer in slow-moving anticyclones, with southwesterly transport and warm, sunny conditions that are favorable for photochemical formation of ozone. The study demonstrates that the use of a sequencing technique in conjunction with a synoptic classification scheme enables a more thorough analysis of the data. © 1992 Taylor & Francis Group, LLC.
• Comrie, A. C., & Yarnal, B. (1992). Relationships between synoptic-scale atmospheric circulation and ozone concentrations in Metropolitan Pittsburgh, Pennsylvania. Atmospheric Environment. Part B, Urban Atmosphere, 26(Issue 3). doi:10.1016/0957-1272(92)90006-e
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  A synoptic climatology demonstrates the relationships between the atmospheric circulation and surface ozone (O3) concentrations. To deduce these associations, a subjective synoptic classification scheme is applied to 10 years' O3 data from the Pittsburgh metropolitan area. The results focus on four aspects of the atmospheric circulation-O3 relationship: average, extreme-event, between season and year-to year conditions. On average, each of the nine circulation types is related to a characteristic O3 concentration level and cumulative O3 dose. Extreme high-O3 events are associated with either the western side of a slowly migrating anticyclone or a stagnating extended high-pressure ridge; low-O3 events are experienced under cool and cloudy cyclonic conditions. Between-season variations in the average and extreme circulation-O3 relationshipsare observed: the high-pressure features that produce the high st O3 levels in summer are related to low levels in winter, while circulation patterns that contribute very little to summertime O3 build-up are associated with the highest levels of wintertime O3. The latter situation could be caused by tropopause folding and the introduction of stratospheric ozone in winter months. While zonal (meridional) circulation regimes tend to produce lower (higher) mean annual O3 levels, such year-to-year changes in synoptic-type frequencies do not appear to be strongly related to interannual variations in O3, and other non-climatic factors appear to be of greater importance. © 1992.
• Comrie, A. C., & Yarnal, B. (1992). Relationships between synoptic-scale atmospheric circulation and ozone concentrations in metropolitan Pittsburgh, Pennsylvania. Atmospheric Environment. Part B. Urban Atmosphere, 26(3), 301--312.
• Simini, M., Skelly, J. M., Davis, D. D., Savage, J. E., & Comrie, A. C. (1992). Sensitivity of four hardwood species to ambient ozone in north central Pennsylvania. Canadian Journal of Forest Research, 22(Issue 11). doi:10.1139/x92-234
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  On ridgetop sites of the Allegheny Plateau, open-top chambers were established in Clear Creek State Park, Jefferson County, Elliott State Park, Clearfield County, and Tiadaghton, Lycoming County. Seedlings of black cherry Prunus serotina, yellow poplar Liriodendron tulipifera, red oak Quercus rubra and red maple Acer rubrum were exposed to ambient air or to charcoal-filtered air containing 95, 60, or 40% of ambient ozone in 1988 and 1989. Black cherry seedlings were also exposed in 1990. Ozone was greatest in 1988 at all sites, and total ozone during the 3-yr study was greatest at the westernmost sites (Clear Creek and Elliott). Foliar stipple injury of black cherry and yellow poplar were correlated positively with ozone within and among sites throughout the study. Premature leaf abscission of both species was significantly greater with higher ozone levels at the Elliott site in 1988 and 1989. Ozone stipple was not observed on red maple and red oak seedlings. Ambient ozone did not significantly decrease height, basal diameter, or leaf surface area of any species. -from Authors
• Simini, M., Skelly, J., Davis, D., Savage, J., & Comrie, A. (1992). Sensitivity of four hardwood species to ambient ozone in north central Pennsylvania. Canadian Journal of Forest Research, 22(11), 1789--1799.
• Comrie, A. C. (1990). The climatology of surface ozone in rural areas: A conceptual model. Progress in Physical Geography, 14(Issue 3). doi:10.1177/030913339001400301
• Comrie, A. C. (1990). The climatology of surface ozone in rural areas: a conceptual model. Progress in Physical Geography, 14(3), 295--316.

Proceedings Publications

• Comrie, A. C., & Glueck, M. F. (2007). Assessment of climate-coccidioidomycosis model: Model sensitivity for assessing climatologic effects on the risk of acquiring coccidioidomycosis. In N/A.
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  Understanding the predictive relationships between climate variability and coccidioidomycosis is of great importance for the development of an effective public health decision-support system. Preliminary regression-based climate modeling studies have shown that about 80% of the variance in seasonal coccidioidomycosis incidence for southern Arizona can be explained by precipitation and dust-related climate scenarios prior to and concurrent with outbreaks. In earlier studies, precipitation during the normally arid foresummer 1.5-2 years prior to the season of exposure was found to be the dominant predictor. Here, the sensitivity of the seasonal modeling approach is examined as it relates to data quality control (QC), data trends, and exposure adjustment methodologies. Sensitivity analysis is based on both the original period of record, 1992-2003, and updated coccidioidomycosis incidence and climate data extending the period of record through 2005. Results indicate that models using case-level data exposure adjustment do not suffer significantly if individual case report data are used "as is." Results also show that the overall increasing trend in incidence is beyond explanation through climate variability alone. However, results also confirm that climate accounts for much of the coccidioidomycosis incidence variability about the trend from 1992 to 2005. These strongly significant relationships between climate conditions and coccidioidomycosis incidence obtained through regression modeling further support the dual "grow and blow" hypothesis for climate-related coccidioidomycosis incidence risk. © 2007 New York Academy of Sciences.
• Comrie, A., Lemos, M., Hughes, M., & Overpeck, J. (2004). Climate science and services: Some lessons from climas. In American Meteorological Society Annual Meeting and 13th Conference on Applied Climatology.
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  The integration of basic climate science and stakeholder interests was carried out by Climate Assessment for the Southwest (CLIMAS) by adopting an iterative model of regional assessment research. The data could be used by all stakeholders to improve their stock situation. CLIMAS integrates the basic climate science and the interests of the stakeholders by making the stakeholders involve and interact in regional assessment research. Its work also involves close interaction with doctors and public health officials to study the environmental factors which affect the climate sensitive diseases. The research results provides evidences in diversified fields of ecology, socioeconomics, and cultural fields.
• McPhee, J., Comrie, A., Garfin, G., McPhee, J., Comrie, A., & Garfin, G. (2004). A climatology of drought for Arizona. In 100th Annual Meeting of the Association of American Geographers.
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  The climatology of drought for Arizona and economic losses suffered in the ranching, agriculture, and tourism sectors was described. Statistical analyses were performed on the data including the annual and long-term mean. The calculations were performed to determine the precipitation percentages for each climate division of Arizona. It was found that two precipitation peaks occur each year in the winter and the summer in Arizona.
• Comrie, A. C., Sheppard, P. R., Packin, G. D., Angersbach, K., & Hughes, M. K. (1999). Assessing climate variability in the Southwest: State of the science. In 29th Annual Water Resources Planning and Management Conference, WRPMD 1999.
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  Dry, and hot! For many, these two words sum up the climate of the southwestern United States. The region's low deserts experience searing heat and desiccating winds in the early summer while, in contrast, the forested mountains and plateaus endure biting cold and drifting snow in the heart of winter. The Southwest may be drenched by torrential monsoon thunderstorms in July and August, yet it can warm gently under fair skies from fall to spring. Records of temperature and precipitation change span time scales shorter than seasons and longer than millennia. Droughts and floods that would make headlines elsewhere are almost routine in the Southwest. Variability is therefore the norm, and climate is always fluctuating within this region. How do we explain the complex climate of the Southwest? How has it changed over time, and what might we expect of future climate? In this paper we aim to answer these and related questions to produce an account of the current state of knowledge of natural climate variability in the Southwest. Specifically: What is our understanding of climate variability in the Southwest on seasonal to inter-decadal time scales and what are the sources of this variability? What are the major patterns or types of variability evident from the instrumental record and natural archives such as tree rings, in terms of extremes, drifts in mean, trends or periodic and quasi periodic features? How typical has the instrumental period (i.e., the 20th century) been in the context of these patterns from natural archives? © 1999 American Society of Civil Engineers.
• Comrie, A. C., Diem, J. E., & Gutheim, T. L. (1998). Development of a GIS-based air quality planning model for marginal attainment areas. In Proceedings of the 1998 91st Annual Meeting & Exposition of the Air & Waste Management Association.
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  We outline the development of an air quality model that integrates air quality, transportation, and related data within a geographic information system (GIS) designed to take advantage of powerful visualization-driven insight and analysis capabilities, with an application to greater metropolitan Tucson, Arizona. The System for Management, Observation, and GIS Modeling of Air Pollution (SMOGMAP) is a planning tool for assessment and evaluation of numerous factors, including transportation control measure impacts, monitor siting, changing growth and emission patterns, and varying climatological and meteorological circumstances. SMOGMAP includes existing, adapted, and newly created spatial databases in a GIS framework that forms an integrated multidimensional matrix of possible planning scenarios for visualization and spatial analysis. The user has control over comparative and analytic operations to produce qualitative or quantitative/statistical output. This kind of tool is particularly suited to areas that have attainment status for many pollutants, but for which there is some risk of non-attainment. In such situations, the financial, human, and computer resources required for complex regulatory models such as the Urban Airshed Model (UAM) are often unavailable (and perhaps not necessary), but a tool such as SMOGMAP can provide relatively inexpensive, valuable planning data and analyses that are upwardly compatible with regulatory models.
• Comrie, A. C. (1996). Determining the climatology of ozone potential for the U.S.-Mexico border. In Proceedings of the 1996 Air & Waste Management Association's 89th Annual Meeting & Exhibition.
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  Ozone pollution in the United States-Mexico border region is increasing due to growth and development of urban and industrial centers on both sides of the international boundary. Ambient ozone concentrations are influenced strongly by atmospheric circulation, which varies considerably Over the US-Mexico borderlands. Concerns have arisen regarding the potential for ozone formation near current and future areas of high precursor emissions. Ozone potential depends on the range of weather patterns that move over the area in question, and thus a sound understanding of climatological controls on border-region ozone is required. This study uses an existing synoptic climatology to analyze a range of ozone data from the borderlands. The regional, or synoptic, scale is the primary weather-system scale controlling border region climate, especially those variables affecting air quality. The synoptic climatology comprises six characteristic circulation patterns based on gridded 850 mb pressure-height data from 1963 to 1994. The synoptic catalog is combined with surface weather data for sites located throughout the region. Ozone data for varying lengths of record from the mid-1970s to 1994 were extracted from the EPA AIRS database and other available sources. Relationships between circulation patterns, weather conditions and ozone were determined by statistical modeling. Results show that the border region is differentially susceptible to high-ozone weather conditions. Associated suites of weather variables influence ambient ozone concentrations under each circulation pattern, resulting in a spatially and temporally distinct 'ozone footprint' for the region. Climate data are more readily generalized than site-specific ozone data, and thus climate-related potentials for ozone pollution are inferred for unmonitored areas of the US-Mexico border region.

Presentations

• Bieda, S., Comrie, A. C., Crimmins, M. A., Byerle, L., & Brost, J. (2014, October). Flash Flood Causing Mechanisms of the North American Monsoon in the Sonoran Desert. 39th Annual Meeting of the National Weather Association. Salt Lake City, UT: National Weather Association.
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  The relationship of flash flood reports to gulf surges and upper-tropospheric troughs are explored based on the variability of hourly precipitation and lightning data over the southwestern United States from 1996 to 2011. Using a variety of upper-level, mid-level and surface level datasets, chi-square analysis, Student's t-test and Monte Carlo field significance tests are conducted to determine whether the presence of synoptic-scale and mesoscale features provide a significant enhancement to the convective environment. This method is used in 3-hourly normalized time steps to determine the environment that can be expected when inverted troughs, gulf surges, the presence of both features or the absence of both features are expected utilizing precipitation and lightning fields. The National Weather Service Storm Reports are explored for instances of short-term, heavy precipitation flood events, to include flash floods, heavy precipitation, and urban and small stream floods. These reports were found to have a statistically significant relationship when compared against a climatological database of inverted troughs and gulf surges. When inverted troughs and gulf surges are present in the study region, a statistically significant increase of both lightning counts and precipitation totals were found. When neither feature was recorded, a significant downturn of both lightning counts and precipitation were noted. These results point to potential "burst" period mechanisms during the monsoon season, specifically with regards to synoptic-scale disturbances and gulf surges over the study domain.