Joellen L Russell
- Associate Professor, Geosciences
- Associate Professor, Planetary Sciences
- Associate Professor, Lunar and Planetary Laboratory
- Associate Professor, Global Change - GIDP
- Associate Professor, Applied Mathematics - GIDP
- Associate Professor, Hydrology / Atmospheric Sciences
Joellen Russell's work on the westerly winds led to the creation of a new paradigm in climate science, namely that warmer climates produce stronger westerly winds. This insight solved one of the long-standing climate paradoxes, the mechanism responsible for transferring one-third of the carbon dioxide in the atmosphere into the ocean and then back out again during our repeated glacial-interglacial cycles.
Dr. Russell joined the faculty in the Department of Geosciences at the University of Arizona in 2006. She uses climate models and supercomputers like those at the new UA Research Data Center to simulate the earth system in the future, the present and the past. Prof. Russell was named a University of Arizona 1885 Society Distinguished Scholar in 2014 and won the UA Provost’s Teaching Award in 2010. Joellen Russell received her bachelor's degree at Harvard University in Environmental Geoscience and earned her Ph.D. at Scripps Institution of Oceanography, UCSD in Oceanography. Before joining the faculty in the Department of Geosciences at the University of Arizona in 2006, she worked at Princeton University at NOAA's Geophysical Fluid Dynamics Laboratory during the intensive preparations for the Intergovernmental Panel on Climate Change Fourth Assessment.
Joellen grew up north of the Arctic Circle in an Eskimo fishing village and began actively working toward her current position at the age of 12 - she can’t believe she gets paid to work on the biggest challenge of our time. She lives in Tucson with her husband and their two children.
- Ph.D. Oceanography
- Scripps Institution of Oceanography, University of California - San Diego, San Diego, California, USA
- The Biogeochemistry of Southern Ocean Intermediate and Mode Waters
- B.A. Environmental Geoscience
- Harvard University, Boston, Massachusetts, USA
- Applying Geology to Atmospheric Research: Modern Analogs to Archean Paleosols
- Visiting Scientist, NOAA's Geophysical Fluid Dynamics Laboratory (2013)
- Visiting Fellow, Princeton University, Princeton, New Jersey (2013)
- Associate Professor, University of Arizona, Deptartment of Geoscience and Department of Planetary Science (2012 - Ongoing)
- Assistant Professor, University of Arizona, Department of Geoscience (2006 - 2012)
- Research Scientist, Princeton University, Program in Atmospheric and Oceanic Sciences (2002 - 2006)
- Postdoctoral Research Associate, University of Washington, Joint Institute for the Study of Atmosphere and Ocean, Department of Atmospheric Sciences (1999 - 2002)
- Thomas R. Brown Distinguished Chair of Integrative Science
- Thomas R. Brown Foundation, Fall 2017
- 1885 Society Distinguished Scholar
- University of Arizona Foundation’s 1885 Society, Spring 2014
- Distinguished Lecturer
- American Association of Petroleum Geologists, Fall 2011
- Provost’s General Education Teaching Award
- University of Arizona, Spring 2010
Our planet is vast, complicated and dynamic, and we live in a time of great change. As an undergraduate, I benefited from professors who lived William Butler Yeats’ attitude about teaching, “Education is not filling a bucket, but lighting a fire.” I now strive to emulate my mentors in my own teaching. Sharing the passion and drive for understanding of both the known and unknown with my students is one of the great joys of working here at the University of Arizona. The terrific advantage of teaching and learning at a major research university is the opportunity to use the very latest tools to help our students make their own discoveries about their planet. Over the past 4 years, I have taught over 3000 students and co-taught hundreds more. My research benefits daily from the energy and enthusiasm our students bring to their work.My students don’t come into class as clean slates – they have their own interests, experiences and perspectives. I want to learn what they know and think, and for them to take what I have to offer and integrate it into their own lives. I learn from my students, because I know that I have glimpsed only a tiny slice of life and that I am bound by the limits of my own time and experience. The future belongs to these bright, motivated individuals and it is my privilege to help them prepare for it.
Prof. Russell's research focuses on the ocean's role in climate. Her main focus has been on the Southern Ocean, which accounts for up to half of the annual oceanic uptake of anthropogenic carbon dioxide from the atmosphere and for about 70% of the excess heat that is transferred from the atmosphere into the ocean each year. The functioning of the Southern Ocean is intimately tied to the strength and position of the westerly winds, so a significant part of her research has been uncovering the climatic factors that determine the strength and latitudinal position of these winds. She uses the latest global coupled climate models and the latest Earth System Models to address the critical problems in climate science (in the present, the near and longer-term future, the recent past, and the deep past).Prof. Russell’s earlier work on the westerly winds led to her greatest research accomplishment so far: the creation of a new paradigm in climate science, namely that warmer climates produce stronger westerly winds. This insight solved one of the long-standing climate paradoxes, the mechanism responsible for transferring one-third of the carbon dioxide in the atmosphere into the ocean and then back out again during our repeated glacial-interglacial cycles.Prof. Russell continues active collaboration with the GFDL Earth System Model and Climate Model Development Teams, and is currently serving as a member of the U.S. Carbon Cycle Science Steering Group and as a member of the international CLIVAR/CliC/SCAR Southern Ocean Region Panel
DissertationGEOS 920 (Spring 2018)
Independent StudyGEOS 599 (Spring 2018)
ResearchGEOS 900 (Spring 2018)
Special Topics in ScienceHNRS 195I (Spring 2018)
DissertationGEOS 920 (Fall 2017)
Intro To OceanographyGEOS 212 (Fall 2017)
ResearchGEOS 900 (Fall 2017)
Teaching GeosciencesGEOS 397A (Fall 2017)
DissertationGEOS 920 (Spring 2017)
GeosciencesGEOS 596H (Spring 2017)
Independent StudyGEOS 499 (Spring 2017)
Independent StudyGEOS 599 (Spring 2017)
ResearchGEOS 900 (Spring 2017)
DissertationGEOS 920 (Fall 2016)
Independent StudyGEOS 499 (Fall 2016)
Independent StudyGEOS 599 (Fall 2016)
Intro To OceanographyGEOS 212 (Fall 2016)
ResearchGEOS 900 (Fall 2016)
Teaching GeosciencesGEOS 397A (Fall 2016)
- Cayan, D., Tyree, M., Kunkel, K., Castro, C., Gershunov, A., Barsugli, J., Ray, A., Overpeck, J., Anderson, M., Russell, J., Rajagopalan, B., Rangwala, I., & Duffy, P. (2013). Future Climate: Projected Average. In Assessment of Climate Change in the Southwest United States: A Report Prepared for the National Climate Assessment(pp 101-125). Washington, DC: Island Press.More infoEditor(s): Garfin, G; Jardine, A; Merideth, R; Black, M; LeRoy, S. A report by the Southwest Climate Alliance
- Russell, J. (2018). Ocean sensors can track progress on climate goals. Nature, 555, 287. doi:doi: 10.1038/d41586-018-03068-w
- Russell, J. L., Kamenkovich, I., Bitz, C., Ferrari, R., Gille, S. T., Goodman, P. J., Hallberg, R., Johnson, K., Khazmutdinova, K., Marinov, I., Mazloff, M., Sarmiento, J. L., Speer, K., Talley, L. D., & Wanninkhof, R. (2018). Metrics for the Evaluation of the Southern Ocean in Coupled Climate and Earth System Models. Journal of Geophysical Research - Oceans, 123, 1-24. doi:https://doi.org/10.1002/ 2017JC013461More infoThe Southern Ocean is central to the global climate and the global carbon cycle, and to the climate's response to increasing levels of atmospheric greenhouse gases, as it ventilates a large fraction of the global ocean volume. Global coupled climate models and earth system models, however, vary widely in their simulations of the Southern Ocean and its role in, and response to, the ongoing anthropogenic trend. Due to the region's complex water-mass structure and dynamics, Southern Ocean carbon and heat uptake depend on a combination of winds, eddies, mixing, buoyancy fluxes, and topography. Observationally-based metrics are critical for discerning processes and mechanisms, and for validating and comparing climate and earth system models. New observations and understanding have allowed for progress in the creation of observationally-based data/model metrics for the Southern Ocean. Metrics presented here provide a means to assess multiple simulations relative to the best available observations and observational products. Climate models that perform better according to these metrics also better simulate the uptake of heat and carbon by the Southern Ocean. This report is not strictly an intercomparison, but rather a distillation of key metrics that can reliably quantify the “accuracy” of a simulation against observed, or at least observable, quantities. One overall goal is to recommend standardization of observationally-based benchmarks that the modeling community should aspire to meet in order to reduce uncertainties in climate projections, and especially uncertainties related to oceanic heat and carbon uptake.
- Williams, N. L., Juranek, L. W., Feely, R. A., Russell, J. L., Johnson, K. S., & Hales, B. (2018). Assessment of the carbonate chemistry climate in the Southern Ocean from persistent observational platforms. J. Geophysical Research – Oceans. doi:https://doi.org/10.1029/2017JC012917
- Bronselaer, B., Winton, M., Russell, J. L., Sabine, C. L., & Khatiwala, S. (2017). Agreement of CMIP5 Simulated and Observed Ocean Anthropogenic CO2 Uptake. Geophysical Research Letters, 44, 12,298–12,305. doi:https://doi.org/10.1002/2017GL074435More infoPrevious studies found large biases between individual observational and model estimates of historical ocean anthropogenic carbon uptake. We show that the largest bias between the Coupled Model Intercomparison Project phase 5 (CMIP5) ensemble mean and between two observational estimates of ocean anthropogenic carbon is due to a difference in start date. After adjusting the CMIP5 and observational estimates to the 1791–1995 period, all three carbon uptake estimates agree to within 3 Pg of C, about 4% of the total. The CMIP5 ensemble mean spatial bias compared to the observations is generally smaller than the observational error, apart from a negative bias in the Southern Ocean and a positive bias in the Southern Indian and Pacific Oceans compensating each other in the global mean. This dipole pattern is likely due to an equatorward and weak bias in the position of Southern Hemisphere westerlies and lack of mode and intermediate water ventilation.
- Naiman, Z., Goodman, P. J., Krasting, J. P., Malyshev, S. L., Russell, J. L., Stouffer, R. J., & Wittenberg, A. T. (2017). Impact of mountains on tropical circulation in two Earth System Models. Journal of Climate, 30, 4149-4163. doi:DOI: http://dx.doi.org/10.1175/JCLI-D-16-0512.1More infoTwo state-of-the-art Earth System Models (ESMs) were used in an idealized experiment to explore the role of mountains in shaping Earth’s climate system. Similar to previous studies, removing mountains from both ESMs results in the winds becoming more zonal, and weaker Indian and Asian monsoon circulations. However, there are also broad changes to the Walker circulation and the El Niño Southern Oscillation (ENSO). Without orography, convection moves across the entire equatorial Indo-Pacific basin on interannual timescales. The ENSO has a stronger amplitude, lower frequency and increased regularity. A wider equatorial wind zone and changes to equatorial wind stress curl result in a colder cold tongue and a steeper equatorial thermocline across the Pacific basin during La Niña years. Anomalies associated with ENSO warm events are larger without mountains, and have greater impact on the mean tropical climate than when mountains are present. Without mountains the centennial-mean Pacific Walker circulation weakens in both models by ~45%, but the strength of the mean Hadley circulation changes by
- Naiman, Z., Goodman, P. J., Krasting, J. P., Malyshev, S. L., Russell, J. L., Stouffer, R. J., & Wittenberg, A. T. (2017). Impact of mountains on tropical circulation in two Earth System Models. Journal of Climate. doi:http://dx.doi.org/10.1175/JCLI-D-16-0512.1
- Williams, N. L., Juranek, L. W., Feely, R. A., Johnson, K. S., Sarmiento, J. L., Talley, L. D., Dickson, A. G., Gray, A. R., Wanninkhof, R., Russell, J. L., Riser, S. C., & Takeshita, Y. (2017). Calculating surface ocean pCO2 from biogeochemical Argo floats equipped with pH: an uncertainty analysis. Global Biogeochemical Cycles, n/a--n/a. doi:10.1002/2016GB005541More infoMore than 74 biogeochemical profiling floats that measure water column pH, oxygen, nitrate, fluorescence, and backscattering at 10-day intervals have been deployed throughout the Southern Ocean. Calculating the surface ocean partial pressure of carbon dioxide (pCO2sw) from float pH has uncertainty contributions from the pH sensor, the alkalinity estimate, and carbonate system equilibrium constants, resulting in a relative standard uncertainty in pCO2sw of 2.4% (or 10 µatm at pCO2sw of 400 µatm). The calculated pCO2sw from several floats spanning a range of oceanographic regimes are compared to existing climatologies. In some locations, such as the Subantarctic zone, the float data closely match the climatologies, but in the Polar Antarctic Zone significantly higher pCO2sw are calculated in the wintertime implying a greater air-sea CO2 efflux estimate. Our results based on four representative floats suggest that despite their uncertainty relative to direct measurements the float data can be used to improve estimates for air-sea carbon flux, as well as to increase knowledge of spatial, seasonal, and interannual variability in this flux.
- Wynn, J., Campisano, C., Cohen, A. S., Trauth, M., Stone, J., Arrowsmith, J. R., Schaebitz, F., Asrat, A., Russell, J. L., Behrensmeyer, A. K., Russell, J., Brown, E., Renaut, R., Deino, A., Reed, K., Deocampo, D., Feibel, C., Potts, R., Pelletier, J. D., , Kingston, J., et al. (2017). The Hominin Sites and Paleolakes Drilling Project: Acquiring High-Resolution Paleoclimate Records from the East African Rift System and Their Implications for Understanding the Environmental Context of Hominin Evolution. Paleoanthropology, 2017, 1-43. doi:doi: 10.4207/PA.2017.ART104More infoThe possibility of a causal relationship between Earth history processes and hominin evolution in Africa has been the subject of intensive paleoanthropological research for the last 25 years. One fundamental question is: can any geohistorical processes, in particular, climatic ones, be characterized with sufficient precision to enable temporal correlation with events in hominin evolution and provide support for a possible causal mechanism for evolutionary changes? Previous attempts to link paleoclimate and hominin evolution have centered on evidence from the outcrops where the hominin fossils are found, as understanding whether and how hominin populations responded to habitat change must be examined at the local basinal scale. However, these outcrop records typically provide incomplete, low-resolution climate and environmental histories, and surface weathering often precludes the application of highly sensitive, state-of-the-art paleoenvironmental methods. Continuous and well-preserved deep-sea drill core records have provided an alternative approach to reconstructing the context of hominin evolution, but have been collected at great distances from hominin sites and typically integrate information over vast spatial scales. The goal of the Hominin Sites and Paleolakes Drilling Project (HSPDP) is to analyze climate and other Earth system dynamics using detailed paleoenvironmental data acquired through scientific drilling of lacustrine depocenters at or near six key paleoanthropological sites in Kenya and Ethiopia. This review provides an overview of a unique collaboration of paleoanthropologists and earth scientists who have joined together to explicitly explore key hypotheses linking environmental history and mammalian (including hominin) evolution and potentially develop new testable hypotheses. With a focus on continuous, high-resolution proxies at timescales relevant to both biological and cultural evolution, the HSPDP aims to dramatically expand our understanding of the environmental history of eastern Africa during a significant portion of the Late Neogene and Quaternary, and to generate useful models of long-term environmental dynamics in the region.
- Chang, C., Burr, G. S., Jull, A. J., Russell, J. L., Biddulph, D., White, L., Prouty, N. G., Chen, Y., Shen, C., Zhou, W., & Lam, D. D. (2016). Reconstructing Surface Ocean circulation with 129I time series records from corals. J. Environmental Radioactivity, 165, 144-150. doi:http://dx.doi.org/10.1016/j.jenvrad.2016.09.016More infoThe long-lived radionuclide 129I (half-life: 15.7 × 106 yr) is well-known as a useful environmental tracer. At present, the global 129I in surface water is about 1-2 orders of magnitude higher than pre-1960 levels. Since the 1990s, anthropogenic 129I produced from industrial nuclear fuels reprocessing plants has been the primary source of 129I in marine surface waters of the Atlantic and around the globe. Here we present four coral 129I time series records from: 1) Con Dao and 2) Xisha Islands, the South China Sea, 3) Rabaul, Papua New Guinea and 4) Guam. The Con Dao coral 129I record features a sudden increase in 129I in 1959. The Xisha coral shows similar peak values for 129I as the Con Dao coral, punctuated by distinct low values, likely due to the upwelling in the central South China Sea. The Rabaul coral features much more gradual 129I increases in the 1970s, similar to a published record from the Solomon Islands. The Guam coral 129I record contains the largest measured values for any site, with two large peaks, in 1955 and 1959. Nuclear weapons testing was the primary 129I source in the Western Pacific in the latter part of the 20th Century, notably from testing in the Marshall Islands. The Guam 1955 peak and Con Dao 1959 increases are likely from the 1954 Castle Bravo test, and the Operation Hardtack I test is the most likely source of the 1959 peak observed at Guam. Radiogenic iodine found in coral was carried primarily through surface ocean currents. The coral 129I time series data provide a broad picture of the surface distribution and depth penetration of 129I in the Pacific Ocean over the past 60 years.
- Chang, C., Burr, G. S., Russell, J. L., & Jull, A. J. (2016). Reconstructing surface ocean circulation with 129I time series from corals. Journal of Environmental Radioactivity, 165, 144-150.
- Cohen, A. S., Campisano, C., Arrowsmith, R., Asrat, A., Behrensmeyer, A. K., Deino, A., Feibel, C. S., Hill, A., Johnson, R. A., Kingston, J., Lamb, H. F., Lowenstein, T., Noren, A., Olago, D. O., Owen, R. B., Potts, R., Reed, K., Renaut, R., Schabitz, F., , Tiercelin, J., et al. (2016). The Hominin Sites and Paleolakes Drilling Project: Inferring the Environmental Context of Human Evolution from Eastern African Rift Lake Deposits. Scientific Drilling, 21, 1-16. doi:10.5194/sd-21-1-2016
- Cohen, A., Campisano, C., Arrowsmith, R., Asrat, A., Behrensmeyer, A. K., Deino, A., Feibel, C., Hill, A., Johnson, R., Kingston, J., Lamb, H., Lowenstein, T., Noren, A., Olago, D., Owen, R. B., Potts, R., Reed, K., Renaut, R., Sch\"abitz, F., , Tiercelin, J., et al. (2016). The Hominin Sites and Paleolakes Drilling Project: inferring the environmental context of human evolution from eastern African rift lake deposits. Scientific Drilling, 21, 1-16. doi:doi:10.5194/sd-21-1-2016More infoThe role that climate and environmental history may have played in influencing human evolution has been the focus of considerable interest and controversy among paleoanthropologists for decades. Prior attempts to understand the environmental history side of this equation have centered around the study of outcrop sediments and fossils adjacent to where fossil hominins (ancestors or close relatives of modern humans) are found, or from the study of deep sea drill cores. However, outcrop sediments are often highly weathered and thus are unsuitable for some types of paleoclimatic records, and deep sea core records come from long distances away from the actual fossil and stone tool remains. The Hominin Sites and Paleolakes Drilling Project (HSPDP) was developed to address these issues. The project has focused its efforts on the eastern African Rift Valley, where much of the evidence for early hominins has been recovered. We have collected about 2 km of sediment drill core from six basins in Kenya and Ethiopia, in lake deposits immediately adjacent to important fossil hominin and archaeological sites. Collectively these cores cover in time many of the key transitions and critical intervals in human evolutionary history over the last 4 Ma, such as the earliest stone tools, the origin of our own genus Homo, and the earliest anatomically modern Homo sapiens. Here we document the initial field, physical property, and core description results of the 2012–2014 HSPDP coring campaign.
- Williams, N. L., Juranek, L. W., Johnson, K. S., Feely, R. A., Riser, S. C., Talley, L. D., Russell, J. L., Sarmiento, J. L., & Wanninkhof, R. (2016). Empirical Algorithms to Estimate Water Column pH in the Southern Ocean. Geophysical Research Letters, 43, 3415-3422. doi:10.1002/2016gl068539More infoEmpirical algorithms are developed using high-quality GO-SHIP hydrographic measurements of commonly measured parameters (temperature, salinity, pressure, nitrate, and oxygen) that estimate pH in the Pacific sector of the Southern Ocean. The coefficients of determination, R-2, are 0.98 for pH from nitrate (pH(N)) and 0.97 for pH from oxygen (pH(Ox)) with RMS errors of 0.010 and 0.008, respectively. These algorithms are applied to Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) biogeochemical profiling floats, which include novel sensors (pH, nitrate, oxygen, fluorescence, and backscatter). These algorithms are used to estimate pH on floats with no pH sensors and to validate and adjust pH sensor data from floats with pH sensors. The adjusted float data provide, for the first time, seasonal cycles in surface pH on weekly resolution that range from 0.05 to 0.08 on weekly resolution for the Pacific sector of the Southern Ocean.
- Zinaye, B., Yost, C. L., Yadeta, M., Warren, M., Urban, J., Smith, P., Sier, M., Raub, T., Rabideaux, N., Wilson, J., Njagi, D., Negash, E. W., Nambiro, E., Muiruri, V., McNulty, E., McCartney, T., Mbuthia, A., Kimburi, E., Karanja, M., , Junginger, A., et al. (2016). The Hominin Sites and Paleolakes Drilling Project: Inferring the Environmental Context of Human Evolution from Eastern African Rift Lake Deposits. Scientific Drilling, 21, 1-16. doi:10.5194/sd-21-1-2016
- Bracegirdle, T. J., Bertler, N., Carleton, A. M., Ding, Q., Fogwill, C. J., Fyfe, J. C., Hellmer, H. H., Karpechko, A. Y., Kusahara, K., Larour, E., Mayewski, P. A., Meier, W. N., Polvani, L. M., Russell, J. L., Stevenson, S. L., Turner, J., van, W., van, d., & Wainer, I. (2016). A Multidisciplinary Perspective on Climate Model Evaluation For Antarctica. Bull. Amer. Meteor. Soc., 97, ES23-ES26.
- Cohen, A. S., Zinaye, B., Campisano, C., Yost, C. L., Arrowsmith, R., Yadeta, M., Asrat, A., Warren, M., Behrensmeyer, A. K., Urban, J., Deino, A., Smith, P., Feibel, C. S., Sier, M., Hill, A., Raub, T., Johnson, R. A., Rabideaux, N., Kingston, J., , Wilson, J., et al. (2016). The Hominin Sites and Paleolakes Drilling Project: Inferring the Environmental Context of Human Evolution from Eastern African Rift Lake Deposits. Scientific Drilling, 21, 1-16. doi:10.5194/sd-21-1-2016
- Downes, S. M., Weijer, W., Jeffrey, N., Mazloff, M., & Russell, J. L. (2015). Southern Ocean Dynamics and Biogeochemistry in a Changing Climate: Introduction and Overview. Deep-Sea Research II, 114, 1-2. doi:doi:10.1016/j.dsr2.2015.02.013
- Kapp, P., Kapp, P., Pullen, A., Pullen, A., Pelletier, J. D., Pelletier, J. D., Russell, J. L., Russell, J. L., Goodman, P. J., Goodman, P. J., Cai, F., Cai, F., Kapp, P., Pullen, A., Pelletier, J. D., Russell, J. L., Goodman, P. J., & Cai, F. (2015). From dust to dust: Quaternary wind erosion of the Mu Us Desert and Loess Plateau, China. Geology.
- Lora, J. M., Lunine, J. I., & Russell, J. L. (2015). GCM Simulations of Titan’s Middle and Lower Atmosphere and Comparison to Observations. Icarus, 250, 516-528.More infoSimulation results are presented from a new general circulation model (GCM) of Titan, the Titan Atmospheric Model (TAM), which couples the Flexible Modeling System (FMS) spectral dynamical core to a suite of external/sub-grid-scale physics. These include a new non-gray radiative transfer module that takes advantage of recent data from Cassini-Huygens, large-scale condensation and quasi-equilibrium moist convection schemes, a surface model with "bucket" hydrology, and boundary layer turbulent diffusion. The model produces a realistic temperature structure from the surface to the lower mesosphere, including a stratopause, as well as satisfactory superrotation. The latter is shown to depend on the dynamical core's ability to build up angular momentum from surface torques. Simulated latitudinal temperature contrasts are adequate, compared to observations, and polar temperature anomalies agree with observations. In the lower atmosphere, the insolation distribution is shown to strongly impact turbulent fluxes, and surface heating is maximum at mid-latitudes. Surface liquids are unstable at mid- and low-latitudes, and quickly migrate poleward. The simulated humidity profile and distribution of surface temperatures, compared to observations, corroborate the prevalence of dry conditions at low latitudes. Polar cloud activity is well represented, though the observed mid-latitude clouds remain somewhat puzzling, and some formation alternatives are suggested.
- MAYEWSKI, P. A., BRACEGIRDLE, T., GOODWIN, I., SCHNEIDER, D., BERTLER, N. A., BIRKEL, S., CARLETON, A., ENGLAND, M. H., KANG, J., KHAN, A., RUSSELL, J., TURNER, J., & VELICOGNA, I. (2015). Potential for Southern Hemisphere climate surprises. Journal of Quaternary Science, 30, 391--395.
- Williams, N. L., Feely, R. A., Sabine, C. L., Dickson, A. G., Swift, J., Talley, L. D., & Russell, J. L. (2015). Quantifying Anthropogenic Carbon Inventory Changes in the Pacific Sector of the Southern Ocean. Marine Chemistry, 174, 147-160. doi:doi:10.1016/j.marchem.2015.06.015
- Wynn, J., Campisano, C., Cohen, A. S., Trauth, M., Stone, J., Arrowsmith, J. R., Asrat, A., Schaebitz, F., Russell, J. L., Behrensmeyer, A. K., Russell, J., Brown, E., Renaut, R., Deino, A., Reed, K., Deocampo, D., Potts, R., Feibel, C., Pelletier, J. D., , Kingston, J., et al. (2017). The Hominin Sites and Paleolakes Drilling Project: Acquiring High-Resolution Paleoclimate Records from the East African Rift System and Their Implications for Understanding the Environmental Context of Hominin Evolution. Paleoanthropology, 2017, 1-43. doi:doi: 10.4207/PA.2017.ART104More infoThe possibility of a causal relationship between Earth history processes and hominin evolution in Africa has been the subject of intensive paleoanthropological research for the last 25 years. One fundamental question is: can any geohistorical processes, in particular, climatic ones, be characterized with sufficient precision to enable temporal correlation with events in hominin evolution and provide support for a possible causal mechanism for evolutionary changes? Previous attempts to link paleoclimate and hominin evolution have centered on evidence from the outcrops where the hominin fossils are found, as understanding whether and how hominin populations responded to habitat change must be examined at the local basinal scale. However, these outcrop records typically provide incomplete, low-resolution climate and environmental histories, and surface weathering often precludes the application of highly sensitive, state-of-the-art paleoenvironmental methods. Continuous and well-preserved deep-sea drill core records have provided an alternative approach to reconstructing the context of hominin evolution, but have been collected at great distances from hominin sites and typically integrate information over vast spatial scales. The goal of the Hominin Sites and Paleolakes Drilling Project (HSPDP) is to analyze climate and other Earth system dynamics using detailed paleoenvironmental data acquired through scientific drilling of lacustrine depocenters at or near six key paleoanthropological sites in Kenya and Ethiopia. This review provides an overview of a unique collaboration of paleoanthropologists and earth scientists who have joined together to explicitly explore key hypotheses linking environmental history and mammalian (including hominin) evolution and potentially develop new testable hypotheses. With a focus on continuous, high-resolution proxies at timescales relevant to both biological and cultural evolution, the HSPDP aims to dramatically expand our understanding of the environmental history of eastern Africa during a significant portion of the Late Neogene and Quaternary, and to generate useful models of long-term environmental dynamics in the region.
- Carrapa, B., Mustapha, F. S., Cosca, M., Gehrels, G. E., Schoenbohm, L. M., Sobel, E. R., Decelles, P. G., Russell, J. L., & Goodman, P. J. (2014). Multisystem dating of modern river detritus from Tajikistan and China: Implications for crustal evolution and exhumation of the Pamir. Lithosphere, 6, 443-455.
- Lora, J., Lunine, J., Russell, J., & Hayes, A. (2014). Simulations of Titan’s Paleoclimate. Icarus, 243, 264-273.
- Ivory, S. J., Russell, J. L., & Cohen, A. S. (2013). In the hot seat: Insolation, ENSO, and vegetation in the African tropics. Journal of Geophysical Research – Biogeosciences, 118, 1347-1358.More infoAbstract African climate is changing at rates unprecedented in the Late Holocene with profound implications for tropical ecosystems and the global hydrologic cycle. Understanding the specific climate drivers behind tropical ecosystem change is critical for both future and paleomodeling efforts. However, linkages between climate and vegetation in the tropics have been extremely controversial. The Normalized Difference Vegetation Index (NDVI) is a satellite-derived index of vegetation productivity with a high spatial and temporal resolution. Here we use regression analysis to show that NDVI variability in Africa is primarily correlated with the interannual extent of the Intertropical Convergence Zone (ITCZ). Our results indicate that interannual variability of the ITCZ, rather than sea surface temperatures or teleconnections to middle/high latitudes, drives patterns in African vegetation resulting from the effects of insolation anomalies and El Niño–Southern Oscillation (ENSO) events on atmospheric circulation. Global controls on tropical atmospheric circulation allow for spatially coherent reconstruction of interannual vegetation variability throughout Africa on many time scales through regulation of dry season length and moisture convergence, rather than precipitation amount.
- Blome, M., Cohen, A., Tryon, C., Brooks, A., & Russell, J. (2012). The environmental context for the origins of modern human diversity: A synthesis of regional variability in African climate 150,000-30,000 years ago. Journal of Human Evolution, 62(5), 563-592.More infoDOI:1016/j.jhevol.2012.01.011
- Russell, J. L., McAfee, S., JL, ., Russell, ., & Webb, R. (2012). Influence of bias correction on simulated landcover changes. Geophysical Research Letters, 39(L16702).More infoDOI:10.1029/2012GL052808
- Kapp, P., Pelletier, J. D., Rohrmann, A., Heermance, R., Russell, J. L., & DIng, L. (2011). Wind erosion in the Qaidam Basin, Central Asia: Implications for tectonics, paleoclimate and the source of the Loess Plateau,. GSA Today, 21(4/5), 4-10.
- Lora, J. M., Goodman, P. J., Russell, J. L., & Lunine, J. I. (2011). Insolation in Titan's troposphere. Icarus, 216(1), 116-119.More infoAbstract: Seasonality in Titan's troposphere is driven by latitudinally varying insolation. We show that the latitudinal distributions of insolation in the troposphere and at the surface, based on Huygens DISR measurements, can be approximated analytically with nonzero extinction optical depths τ, and are not equivalent to that at the top of the atmosphere (τ= 0), as has been assumed previously. This has implications for the temperature distribution and the circulation, which we explore with a simple box model. The surface temperature maximum and the upwelling arm of thermally-direct meridional circulation reach the midlatitudes, not the poles, during summertime. © 2011 Elsevier Inc.
- McAfee, S. A., Russell, J. L., & Goodman, P. J. (2011). Evaluating IPCC AR4 cool-season precipitation simulations and projections for impacts assessment over North America. Climate Dynamics, 37(11-12), 2271-2287.More infoAbstract: General circulation models (GCMs) have demonstrated success in simulating global climate, and they are critical tools for producing regional climate projections consistent with global changes in radiative forcing. GCM output is currently being used in a variety of ways for regional impacts projection. However, more work is required to assess model bias and evaluate whether assumptions about the independence of model projections and error are valid. This is particularly important where models do not display offsetting errors. Comparing simulated 300-hPa zonal winds and precipitation for the late 20th century with reanalysis and gridded precipitation data shows statistically significant and physically plausible associations between positive precipitation biases across all models and a marked increase in zonal wind speed around 30°N, as well as distortions in rain shadow patterns. Over the western United States, GCMs project drier conditions to the south and increasing precipitation to the north. There is a high degree of agreement between models, and many studies have made strong statements about implications for water resources and about ecosystem change on that basis. However, since one of the mechanisms driving changes in winter precipitation patterns appears to be associated with a source of error in simulating mean precipitation in the present, it suggests that greater caution should be used in interpreting impacts related to precipitation projections in this region and that standard assumptions underlying bias correction methods should be scrutinized. © 2011 Springer-Verlag.
- Yin, J., Overpeck, J. T., Griffies, S. M., Aixue, H. u., Russell, J. L., & Stouffer, R. J. (2011). Different magnitudes of projected subsurface ocean warming around Greenland and Antarctica. Nature Geoscience, 4(8), 524-528.More infoAbstract: The observed acceleration of outlet glaciers and ice flows in Greenland and Antarctica is closely linked to ocean warming, especially in the subsurface layer1-5. Accurate projections of ice-sheet dynamics and global sea-level rise therefore require information of future ocean warming in the vicinity of the large ice sheets. Here we use a set of 19 state-of-the-art climate models to quantify this ocean warming in the next two centuries. We find that in response to a mid-range increase in atmospheric greenhouse-gas concentrations, the subsurface oceans surrounding the two polar ice sheets at depths of 200-500 m warm substantially compared with the observed changes thus far6-8. Model projections suggest that over the course of the twenty-first century, the maximum ocean warming around Greenland will be almost double the global mean, with a magnitude of 1.7-2.0 °C. By contrast, ocean warming around Antarctica will be only about half as large as global mean warming, with a magnitude of 0.5-0.6 °C. A more detailed evaluation indicates that ocean warming is controlled by different mechanisms around Greenland and Antarctica. We conclude that projected subsurface ocean warming could drive significant increases in ice-mass loss, and heighten the risk of future large sea-level rise. © 2011 Macmillan Publishers Limited. All rights reserved.
- Ainley, D., Russell, J., Jenouvrier, S., Woehler, E., Lyver, P. O., Fraser, W. R., & Kooyman, G. L. (2010). Antarctic penguin response to habitat change as earth's troposphere reaches 2° C above preindustrial levels. Ecological Monographs, 80(1), 49-66.More infoAbstract: We assess the response of pack ice penguins, Emperor (Aptenodytes forsteri) and Adélie (Pygoscelis adeliae), to habitat variability and, then, by modeling habitat alterations, the qualitative changes to their populations, size and distribution, as Earth's average tropospheric temperature reaches 2°C above preindustrial levels (ca. 1860), the benchmark set by the European Union in efforts to reduce greenhouse gases. First, we assessed models used in the Intergovernmental Panel on Climate Change Fourth Assessment Report (AR4) on penguin performance duplicating existing conditions in the Southern Ocean. We chose four models appropriate for gauging changes to penguin habitat: GFDL-CM2.1, GFDL-CM2.0, MIROC3.2(hi-res), and MRI-CGCM2.3.2a. Second, we analyzed the composited model ENSEMBLE to estimate the point of 2°C warming (2025-2052) and the projected changes to sea ice coverage (extent, persistence, and concentration), sea ice thickness, wind speeds, precipitation, and air temperatures. Third, we considered studies of ancient colonies and sediment cores and some recent modeling, which indicate the (space/time) large/centennialscale penguin response to habitat limits of all ice or no ice. Then we considered results of statistical modeling at the temporal interannual-decadal scale in regard to penguin response over a continuum of rather complex, meso- to large-scale habitat conditions, some of which have opposing and others interacting effects. The ENSEMBLE meso/decadal-scale output projects a marked narrowing of penguins' Zoogeographic range at the 2°C point. Colonies north of 70° S are projected to decrease or disappear: ∼50% of Emperor colonies (40% of breeding population) and ∼75% of Adélie colonies (70% of breeding population), but limited growth might occur south of 73° S. Net change would result largely from positive responses to increase in polynya persistence at high latitudes, overcome by decreases in pack ice cover at lower latitudes and, particularly for Emperors, ice thickness. Adélie Penguins might colonize new breeding habitat where concentrated pack ice diverges and/or disintegrating ice shelves expose coastline. Limiting increase will be decreased persistence of pack ice north of the Antarctic Circle, as this species requires daylight in its wintering areas. Adélies would be affected negatively by increasing snowfall, predicted to increase in certain areas owing to intrusions of warm, moist marine air due to changes in the Polar Jet Stream. © 2010 by the Ecological Society of America.
- Blight, L. K., Ainley, D. G., Ackley, S. F., Ballard, G., Ballerini, T., Brownell Jr., R. L., Cheng, C. C., Chiantore, M., Costa, D., Coulter, M. C., Dayton, P., Devries, A. L., Dunbar, R., Earle, S., Eastman, J. T., Emslie, S. D., Evans, C. W., Garrott, R. A., Kim, S., , Kooyman, G., et al. (2010). Fishing for data in the Ross Sea. Science, 330(6009), 1316-.More infoPMID: 21127229;
- Woodhouse, C. A., Russell, J. L., & Cook, E. R. (2009). Two modes of North American drought from instrumental and paleoclimatic data. Journal of Climate, 22(16), 4336-4347.More infoAbstract: Droughts, which occur as a part of natural climate variability, are expected to increase in frequency and/or severity with global climate change. An improved understanding of droughts and their association with atmospheric circulation will add to the knowledge about the controls on drought, and the ways in which changes in climate may impact droughts. In this study, 1) major drought patterns across the United States have been defined, 2) the robustness of these patterns over time using tree-ring-based drought reconstructions have been evaluated, and 3) the drought patterns with respect to global atmospheric pressure patterns have been assessed. From this simple assessment, it is suggested that there are two major drought patterns across North America, which together account for about 30% of the total variance in drought patterns - one resembles the classic ENSO teleconnection, and the other displays an east-west drought dipole. The same two patterns are evident in the instrumental data and the reconstructed drought data for two different periods, 1404-2003 and 900-1350. The 500-mb circulation patterns associated with the two drought patterns suggest that the controls on drought may come from both Northern Hemisphere and tropical sources. The two drought patterns, and presumably their associated circulation patterns, vary in strength over time, indicating the combined effects of the two patterns on droughts over the past millennium. © 2009 American Meteorological Society.
- McAfee, S. A., & Russell, J. L. (2008). Northern annular mode impact on spring climate in the western United States. Geophysical Research Letters, 35(17).More infoAbstract: Shifts in stormtrack position associated with the Northern Annular Mode (NAM) are linked to temperature changes and reduced spring precipitation in the western United States. During the transition to spring following a high-index winter, weakening of the stormtrack over the northeastern Pacific Ocean and western United States is shown to lead to warmer and drier conditions west of the Rocky Mountains and increased precipitation just east of the Rocky Mountains, consistent with observations of early spring onset in the western United States. Given projected increases in the average annular mode index and associated poleward shifts in the stormtrack, this analysis provides additional evidence that much of the western United States will experience more severe drought conditions over the next several decades, irrespective of changes in temperature, because of an earlier shift to warm-season circulation patterns. Copyright 2008 by the American Geophysical Union.
- Toggweiler, J. R., & Russell, J. (2008). Ocean circulation in a warming climate. Nature, 451(7176), 286-288.More infoPMID: 18202645;Abstract: Climate models predict that the ocean's circulation will weaken in response to global warming, but the warming at the end of the last ice age suggests a different outcome. ©2008 Nature Publishing Group.
- Boer, A. d., Sigman, D. M., Toggweiler, J. R., & Russell, J. L. (2007). Effect of global ocean temperature change on deep ocean ventilation. Paleoceanography, 22(2).More infoAbstract: A growing number of paleoceanographic observations suggest that the ocean's deep ventilation is stronger in warm climates than in cold climates. Here we use a general ocean circulation model to test the hypothesis that this relation is due to the reduced sensitivity of seawater density to temperature at low mean temperature; that is, at lower temperatures the surface cooling is not as effective at densifying fresh polar waters and initiating convection. In order to isolate this factor from other climate-related feedbacks we change the model ocean temperature only where it is used to calculate the density (to which we refer below as "dynamic" temperature change). We find that a dynamically cold ocean is globally less ventilated than a dynamically warm ocean. With dynamic cooling, convection decreases markedly in regions that have strong haloclines (i.e., the Southern Ocean and the North Pacific), while overturning increases in the North Atlantic, where the positive salinity buoyancy is smallest among the polar regions. We propose that this opposite behavior of the North Atlantic to the Southern Ocean and North Pacific is the result of an energy-constrained overturning. Copyright 2007 by the American Geophysical Union.
- Gnanadesikan, A., Russell, J. L., & Zeng, F. (2007). How does ocean ventilation change under global warming?. Ocean Science, 3(1), 43-53.More infoAbstract: Since the upper ocean takes up much of the heat added to the earth system by anthropogenic global warming, one would expect that global warming would lead to an increase in stratification and a decrease in the ventilation of the ocean interior. However, multiple simulations in global coupled climate models using an ideal age tracer which is set to zero in the mixed layer and ages at 1 yr/yr outside this layer show that the intermediate depths in the low latitudes, Northwest Atlantic, and parts of the Arctic Ocean become younger under global warming. This paper reconciles these apparently contradictory trends, showing that the decreases result from changes in the relative contributions of old deep waters and younger surface waters. Implications for the tropical oxygen minimum zones, which play a critical role in global biogeochemical cycling are considered in detail.
- Russell, J. L., Stouffer, R. J., & Dixon, K. W. (2007). Erratum: (Journal of Climate (2006)). Journal of Climate, 20(16), 4287-.
- Delworth, T. L., Broccoli, A. J., Rosati, A., Stouffer, R. J., Balaji, V., Beesley, J. A., Cooke, W. F., Dixon, K. W., Dunne, J., Dunne, K. A., Durachta, J. W., Findell, K. L., Ginoux, P., Gnanadesikan, A., Gordon, C. T., Griffies, S. M., Gudgel, R., Harrison, M. J., Held, I. M., , Hemler, R. S., et al. (2006). GFDL's CM2 global coupled climate models. Part I: Formulation and simulation characteristics. Journal of Climate, 19(5), 643-674.More infoAbstract: The formulation and simulation characteristics of two new global coupled climate models developed at NOAA's Geophysical Fluid Dynamics Laboratory (GFDL) are described. The models were designed to simulate atmospheric and oceanic climate and variability from the diurnal time scale through multicentury climate change, given our computational constraints. In particular, an important goal was to use the same model for both experimental seasonal to interannual forecasting and the study of multicentury global climate change, and this goal has been achieved. Tw o versions of the coupled model are described, called CM2.0 and CM2.1. The versions differ primarily in the dynamical core used in the atmospheric component, along with the cloud tuning and some details of the land and ocean components. For both coupled models, the resolution of the land and atmospheric components is 2° latitude × 2.5° longitude; the atmospheric model has 24 vertical levels. The ocean resolution is 1° in latitude and longitude, with meridional resolution equatorward of 30° becoming progressively finer, such that the meridional resolution is 1/3° at the equator. There are 50 vertical levels in the ocean, with 22 evenly spaced levels within the top 220 m. The ocean component has poles over North America and Eurasia to avoid polar filtering. Neither coupled model employs flux adjustments. The co ntrol simulations have stable, realistic climates when integrated over multiple centuries. Both models have simulations of ENSO that are substantially improved relative to previous GFDL coupled models. The CM2.0 model has been further evaluated as an ENSO forecast model and has good skill (CM2.1 has not been evaluated as an ENSO forecast model). Generally reduced temperature and salinity biases exist in CM2.1 relative to CM2.0. These reductions are associated with 1) improved simulations of surface wind stress in CM2.1 and associated changes in oceanic gyre circulations; 2) changes in cloud tuning and the land model, both of which act to increase the net surface shortwave radiation in CM2.1, thereby reducing an overall cold bias present in CM2.0; and 3) a reduction of ocean lateral viscosity in the extratropics in CM2.1, which reduces sea ice biases in the North Atlantic. Both models have be en used to conduct a suite of climate change simulations for the 2007 Intergovernmental Panel on Climate Change (IPCC) assessment report and are able to simulate the main features of the observed warming of the twentieth century. The climate sensitivities of the CM2.0 and CM2.1 models are 2.9 and 3.4 K, respectively. These sensitivities are defined by coupling the atmospheric components of CM2.0 and CM2.1 to a slab ocean model and allowing the model to come into equilibrium with a doubling of atmospheric CO2. The output from a suite of integrations conducted with these models is freely available online (see http://nomads.gfdl.noaa.gov/). © 2006 American Meteorological Society.
- Gnanadesikan, A., Dixon, K. W., Griffies, S. M., Balaji, V., Barreiro, M., Beesley, J. A., Cooke, W. F., Delworth, T. L., Gerdes, R., Harrison, M. J., Held, I. M., Hurlin, W. J., Lee, H., Liang, Z., Nong, G., Pacanowski, R. C., Rosati, A., Russell, J., Samuels, B. L., , Song, Q., et al. (2006). GFDL's CM2 global coupled climate models. Part II: The baseline ocean simulation. Journal of Climate, 19(5), 675-697.More infoAbstract: The current generation of coupled climate models run at the Geophysical Fluid Dynamics Laboratory (GFDL) as part of the Climate Change Science Program contains ocean components that differ in almost every respect from those contained in previous generations of GFDL climate models. This paper summarizes the new physical features of the models and examines the simulations that they produce. Of the two new coupled climate model versions 2.1 (CM2.1) and 2.0 (CM2.0), the CM2.1 model represents a major improvement over CM2.0 in most of the major oceanic features examined, with strikingly lower drifts in hydrographic fields such as temperature and salinity, more realistic ventilation of the deep ocean, and currents that are closer to their observed values. Regional analysis of the differences between the models highlights the importance of wind stress in determining the circulation, particularly in the Southern Ocean. At present, major errors in both models are associated with Northern Hemisphere Mode Waters and outflows from overflows, particularly the Mediterranean Sea and Red Sea. © 2006 American Meteorological Society.
- Rusell, J. L., Stouffer, R. J., & Dixon, K. W. (2006). Intercomparison of the Southern Ocean circulations in IPCC coupled model control simulations. Journal of Climate, 19(18), 4560-4575.More infoAbstract: The analyses presented here focus on the Southern Ocean as simulated in a set of global coupled climate model control experiments conducted by several international climate modeling groups. Dominated by the Antarctic Circumpolar Current (ACC), the vast Southern Ocean can influence large-scale surface climate features on various time scales. Its climatic relevance stems in part from it being the region where most of the transformation of the World Ocean's water masses occurs. In climate change experiments that simulate greenhouse gas-induced warming, Southern Ocean air-sea heat fluxes and three-dimensional circulation patterns make it a region where much of the future oceanic heat storage takes place, though the magnitude of that heat storage is one of the larger sources of uncertainty associated with the transient climate response in such model projections. Factors such as the Southern Ocean's wind forcing, heat, and salt budgets are linked to the structure and transport of the ACC in ways that have not been expressed clearly in the literature. These links are explored here in a coupled model context by analyzing a sizable suite of preindustrial control experiments associated with the forthcoming Intergovernmental Panel on Climate Change's Fourth Assessment Report. A framework is developed that uses measures of coupled model simulation characteristics, primarily those related to the Southern Ocean wind forcing and water mass properties, to allow one to categorize, and to some extent predict, which models do better or worse at simulating the Southern Ocean and why. Hopefull his framework will also lead to increased understanding of the ocean's response to climate changes. © 2006 American Meteorological Society.
- Russell, J. L., Dixon, K. W., Gnanadesikan, A., Stouffer, R. J., & Toggweiler, J. R. (2006). The Southern hemisphere westerlies in a warming world: Propping open the door to the deep ocean. Journal of Climate, 19(24), 6382-6390.More infoAbstract: A coupled climate model with poleward-intensified westerly winds simulates significantly higher storage of heat and anthropogenic carbon dioxide by the Southern Ocean in the future when compared with the storage in a model with initially weaker, equatorward-biased westerlies. This difference results from the larger outcrop area of the dense waters around Antarctica and more vigorous divergence, which remains robust even as rising atmospheric greenhouse gas levels induce warming that reduces the density of surface waters in the Southern Ocean. These results imply that the impact of warming on the stratification of the global ocean may be reduced by the poleward intensification of the westerlies, allowing the ocean to remove additional heat and anthropogenic carbon dioxide from the atmosphere. © 2006 American Meteorological Society.
- Stouffer, R. J., Russell, J., & Spelman, M. J. (2006). Importance of oceanic heat uptake in transient climate change. Geophysical Research Letters, 33(17).More infoAbstract: The impact of the differences in the oceanic heat uptake and storage on the transient response to changes in radiative forcing is investigated using two newly developed coupled atmosphere-ocean models. In spite of its larger equilibrium climate sensitivity, one model (CM2.1) has smaller transient globally averaged surface air temperature (SAT) response than is found in the second model (CM2.0). The differences in the SAT response become larger as radiative forcing increases and the time scales become longer. The smaller transient SAT response in CM2.1 is due to its larger oceanic heat uptake. The heat storage differences between the two models also increase with time and larger rates of radiative forcing. The larger oceanic heat uptake in CM2.1 can be traced to differences in the Southern Ocean heat uptake and is related to a more realistic Southern Ocean simulation in the control integration. Copyright 2006 by the American Geophysical Union.
- Toggweiler, J. R., Russell, J. L., & Carson, S. R. (2006). Midlatitude westerlies, atmospheric CO2, and climate change during the ice ages. Paleoceanography, 21(2).More infoAbstract: An idealized general circulation model is constructed of the ocean's deep circulation and CO2 system that explains some of the more puzzling features of glacial-interglacial CO2 cycles, including the tight correlation between atmospheric CO2 and Antarctic temperatures, the lead of Antarctic temperatures over CO2 at terminations, and the shift of the ocean's δ13C Minimum from the North Pacific to the Atlantic sector of the Southern Ocean. These changes occur in the model during transitions between on and off states of the southern overturning circulation. We hypothesize that these transitions occur in nature through a positive feedback that involves the midlatitude westerly winds, the mean temperature of the atmosphere, and the overturning of southern deep water. Cold glacial climates seem to have equatorward shifted westerlies, which allow more respired CO2 to accumulate in the deep ocean. Warm climates like the present have poleward shifted westerlies that flush respired CO2 out of the deep ocean. Copyright 2006 by the American Geophysical Union.
- Griffies, S. M., Gnanadesikan, A., Dixon, K. W., Dunne, J. P., Gerdes, R., Harrison, M. J., Rosati, A., Russell, J. L., Samuels, B. L., Spelman, M. J., Winton, M., & Zhang, R. (2005). Formulation of an ocean model for global climate simulations. Ocean Science, 1(1), 45-79.More infoAbstract: This paper summarizes the formulation of the ocean component to the Geophysical Fluid Dynamics Laboratory's (GFDL) climate model used for the 4th IPCC Assessment (AR4) of global climate change. In particular, it reviews the numerical schemes and physical parameterizations that make up an ocean climate model and how these schemes are pieced together for use in a state-of-the-art climate model. Features of the model described here include the following: (1) tripolar grid to resolve the Arctic Ocean without polar filtering, (2) partial bottom step representation of topography to better represent topographically influenced advective and wave processes, (3) more accurate equation of state, (4) three-dimensional flux limited tracer advection to reduce overshoots and undershoots, (5) incorporation of regional climatological variability in shortwave penetration, (6) neutral physics parameterization for representation of the pathways of tracer transport, (7) staggered time stepping for tracer conservation and numerical efficiency, (8) anisotropic horizontal viscosities for representation of equatorial currents, (9) parameterization of exchange with marginal seas, (10) incorporation of a free surface that accomodates a dynamic ice model and wave propagation, (11) transport of water across the ocean free surface to eliminate unphysical "virtual tracer flux" methods, (12) parameterization of tidal mixing on continental shelves. We also present preliminary analyses of two particularly important sensitivities isolated during the development process, namely the details of how parameterized subgridscale eddies transport momentum and tracers. © 2005 Author(s).
- Russell, J. L., & Wallace, J. M. (2004). Annual carbon dioxide drawdown and the Northern Annular mode. Global Biogeochemical Cycles, 18(1), GB1012 1-8.More infoAbstract: Year-to-year variations in summer drawdown of Northern Hemisphere atmospheric carbon dioxide (CO2) are compared with corresponding year-to-year variations in sea-level pressure (SLP), surface air temperature, and the productivity of land vegetation as inferred from the satellite-derived normalized difference vegetation index (NDVI). Annual values of CO2 drawdown for the years 1980-2000 are estimated from smoothed time series derived directly from individual flask samples at the nine Northern Hemisphere monitoring stations with the most continuous records. The leading principal component of the nine standardized drawdown time series, in which all stations exhibit positive loadings, is used to represent the hemispheric signal in the CO2 drawdown. Linear regression analysis is used to infer the spatial patterns of anomalies in sea-level pressure, surface air temperature, and the NDVI observed during various seasons of years in which the drawdown is anomalously strong. Winters preceding anomalously high drawdown seasons exhibit patterns characteristic of the high index of the Northern Annular Mode (NAM). SLP tends to be anomalously low over the Arctic and high over midlatitudes, and Eurasia tends to be anomalously warm. The pattern of the NDVI observed during the early months of the growing season in years with anomalously high drawdown is indicative of high productivity over Eurasia. These results support the notion that the wintertime NAM influences the annual drawdown of CO2 by modulating winter temperatures that, in turn, affect the productivity of the terrestrial biosphere during the subsequent growing season. Copyright 2004 by the American Geophysical Union.
- Russell, J. L., & Dickson, A. G. (2003). Variability in oxygen and nutrients in South Pacific Antarctic Intermediate Water. Global Biogeochemical Cycles, 17(2), 2-1.More infoAbstract: Calculation of the initial oxygen based on both phosphate and nitrate data collected along three WOCE transects indicates that the common assumption that new Antarctic Intermediate Water (AAIW) is initially saturated with respect to oxygen is incorrect. The initial oxygen concentration of AAIW is shown to be undersaturated, and the degree of undersaturation varies from year to year. Chloroflourocarbon data is used to determined the age of AAIW at various latitudes and a frequency analysis of the variability in the initial oxygen concentrations is presented. Possible implications of this variability to the global carbon cycle are suggested.
- Russell, J. L. (2017, Winter). The Once and Future Battles of Thor and the Midgard Serpent (or the Southern Ocean’s Role in Climate). 2017 American Geophysical Union Fall Meeting. New Orleans, LA: American Geophysical Union.More infoThe use of humor has been shown to be an effective mechanism for communicating science. Exemplars of this approach have successfully used humor to engage audiences across the geophysical sciences in understanding and appreciating of the intricacies of their science. We propose to bring together in a single session, a cross-section of talented communicators of researcher who can display how they incorporate humor in the effective communication of their science. Our session will bring together a cross-section of speakers from AGU’s sections/focus groups to feature their use of humor in the presentation of their science followed by a discussion by a panel of experts critiquing examples of the best and worst use of humor in the presentation. We will ask each of the AGU section/focus group presidents to nominate the scientist from their community who is most notorious for, and effective in, their use of humor in communicating their research.
- Russell, J. L. (2016, April). Southern Ocean Carbon and Climate Observations and Modeling. National Academy of Sciences, Board on Atmospheric Sciences and Climate. Washington, DC: National Academy of Sciences, Board on Atmospheric Sciences and Climate.
- Russell, J. L. (2016, April). Southern Ocean Carbon and Climate Observations and Modeling. Sustained Observations for Carbon Cycle Science and Decision Support. Boulder, CO: UCAR/NCAR/CPAESS.
- Russell, J. L. (2016, April). Southern Ocean Carbon and Climate Observations and Modelling. European Geosciences Union General Assembly 2016. Vienna, Asutria: European Geosciences Union.
- Russell, J. L. (2016, August). High-resolution insight into the role of Antarctica and the Southern Ocean in a high-carbon future. XXXIII SCAR Biennial Meeting and 2014 Open Science Conference. Kuala Lumour, Malaysia: Scientific Committee on Antarctic Research.
- Russell, J. L. (2016, June). Interhemispheric Asymmetry of warming and the Southern Ocean. Earth System Science: The Ronald J. Stouffer Symposium. Princeton, NJ: NOAA/GFDL/Princeton.
- Russell, J. L. (2016, May). Comparing the Sensitivity and Distribution of the Southern Ocean Surface Water pH to Mixing in a High Resolution Coupled Climate Model and the CMIP5 Earth System Models. 4th International Symposium on the Ocean in a High-CO2 World. Hobart, Australia: Australian Research COuncil/CSIRO/IAEA-OA-ICC.
- Russell, J. L. (2016, September). High-resolution insights from coupled climate models into the role of the Southern Ocean in a high-carbon future. CLIVAR Open Science Conference 2016. Qingdao, China: CLIVAR.
- Russell, J. L. (2016, Spring). High-resolution insight into the role of the Southern Ocean in a high-carbon future. 2016 Ocean Sciences Meeting. New Orleans, LA: American Geophysical Union.
- Russell, J. L. (2016, Spring). Ocean’s Role in Climate: Carbon & Heat Uptake in the Anthropocene. Modeling a Living Planet A symposium in honor of Jorge L. Sarmiento. Princeton, NJ: Princeton University.
- Russell, J. L. (2016, Spring). Ocean’s Role inHeat and Carbon Uptake in the Anthropocene. Life Sciences Cafe:. Tempe, AZ: School of Life Sciences, Arizona State University.
- Russell, J. L. (2016, Spring). Propping Open The Door To The Deep Southern Ocean: A SOCCOM Update. Institute of Geophysics Seminar. Austin, TX: University of Texas at Austin, Institute of Geophysics.
- Russell, J. L. (2016, Spring). Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM). NOAA OSM Ocean Carbon PI Meeting. New Orleans, LA: NOAA.
- Abell, J., Abell, J., Abell, J., Goodman, P. J., Goodman, P. J., Goodman, P. J., Russell, J. L., Russell, J. L., & Russell, J. L. (2015, Winter). Observationally-Based Data/Model Metrics from the Southern Ocean Climate Model Atlas. AGU Fall Meeting. San Francisco, CA: American Geophysical Union.
- Goodman, P. J., Goodman, P. J., Russell, J. L., Russell, J. L., Merchant, N. C., Merchant, N. C., Miller, S. J., Miller, S. J., Junega, A., & Junega, A. (2015, Winter). iClimate: a climate data and analysis portal. AGU Fall Meeting. San Francisco, CA: American Geophysical Union.
- Naiman, Z., Naiman, Z., Goodman, P. J., Goodman, P. J., Krasting, J. P., Krasting, J. P., Malyshev, S., Malyshev, S., Russell, J. L., Russell, J. L., Stouffer, R. J., & Stouffer, R. J. (2015, Winter). Mountains and Tropical Circulation. AGU Fall Meeting. San Francisco, CA: American Geophysical Union.
- Russell, J. L. (2015, Fall). Southern Ocean model metrics. CLIVAR/CliC/SCAR Southern Ocean Region Panel, joint with SOOS/WCRP/ESA Workshop on Southern Ocean air-sea fluxes. Frascati, Italy: CLIVAR/CliC/SCAR, joint with SOOS/WCRP/ESA.
- Russell, J. L. (2015, Fall). US CLIVAR Summit: Southern Ocean Update. 2015 US CLIVAR Summit. Tucson, AZ: US CLIVAR.
- Russell, J. L. (2015, Spring). Propping Open The Door To The Deep Southern Ocean: An Update. Southern Ocean Dynamics and Biogeochemistry Workshop. California Institute of Technology, Pasadena, CA: California Institute of Technology.
- Russell, J. L. (2015, Summer). Propping Open The Door To The Deep Southern Ocean: An Update. Gordon Research Conference: Processes at Interfaces: Bridging Spatial, Temporal and Disciplinary Divides from Micro- to Global Scales. Holderness, NH: Gordon Research Conference.
- Russell, J. L. (2015, Summer). Propping Open The Door To The Deep Southern Ocean: An Update. Institute for Marine and Antarctic Studies Colloquium. Hobart, Australia: Institute for Marine and Antarctic Studies.
- Russell, J. L. (2015, Summer). SOCCOM: Southern Ocean Carbon and Climate Observations and Modeling Project. Southern Ocean Observing System Scientific Planning Meeting: Implementing a Southern Ocean Observing System. Hobart, Australia: Southern Ocean Observing System.
- Russell, J. L. (2015, Winter). Ocean’s Role in the Global Carbon Budget: Treaty Verification. Planning a Global BioGeoChemical-Argo Network Workshop. Villefranche-sur-mer, France: Argo.
- Russell, J. L. (2015, Winter). On the occasion of GFDL’s 60th Anniversary: GFDL and The Southern Ocean Obsession. GFDL Diamond Anniversary Symposium. Princeton, NJ: National Oceanic and Atmospheric Administration/Geophysical Fluid Dynamics Laboratory.
- Russell, J. L. (2015, Winter). Precipitation, Orography and Climate Models: Past, Present, and Future. STEPPE Workshop: Increased precipitation extremes in greenhouse conditions: An integrated paleoclimate and anthropogenic perspective. Boulder, CO: Geological Society of America.
- Russell, J. L., & Kamenkovich, I. (2015, Fall). Assessing climate model simulations of the Southern Ocean with standardized, observationally-based metrics. GO-SHIP/Argo/ IOCCP Conference 2015: Sustained ocean observing for the next decade. Galway, Ireland: GO-SHIP/Argo/ IOCCP.
- Russell, J. L., & Kamenkovich, I. (2015, Summer). US CLIVAR/OCB Joint Workshop and Working Groups. Ocean Carbon and Biogeochemistry Summer Workshop. Woods Hole, MA: Ocean Carbon and Biogeochemistry.
- Russell, J. L., Mazloff, M., Gray, A., & Kamenkovich, I. (2015, Winter). Observing System Simulation Experiments: The SOCCOM Perspective. Planning a Global BioGeoChemical-Argo Network Workshop. Villefranche-sur-mer, France: Argo.
- Jull, A. J., Chang, C., Biddulph, D., Tritz, C., Mcintosh, J. C., Priyardashi, A., Thiemens, M., Burr, G. S., & Russell, J. L. (2014, August). Environmental Iodine-129 studies at the University of Arizona. 13th International Conference on Accelerator Mass Spectrometry. Aix-en-Provence, France: AMS-13 Conference.
- Russell, J. L. (2014, August). The Ocean's Role in Climate: CMIP5 Projections of the Southern Ocean and Antarctica. XXXIII SCAR Biennial Meetings and Open Science Conference. Auckland, New Zealand.More infoThe Antarctic continent and the surrounding Southern Ocean have significant impacts on the global climate and the climate system’s response to increasing greenhouse forcing. Vertical exchange in the Southern Ocean provides a pathway between the deep and surface waters of the ocean and between the surface ocean and the atmosphere, giving it a disproportionate influence on the climate system. The Antarctic continent and the dynamics of the polar vortex over it influence the stratosphere/troposphere temperature gradient and therefore the strength and position of the southern hemisphere westerly winds. In climate change experiments, Southern Ocean circulation patterns make it a region where much of the future oceanic heat and carbon uptake takes place, although the general circulation around Antarctica and the magnitude of the uptake are several of the larger sources of uncertainty associated with the transient climate response, especially in the latest Earth System Models that explicitly simulate the carbon cycle. We will assess this uptake and other significant variables in future simulations from the suite of CMIP5 Earth System Models as well as in the ultrahigh resolution, eddy-resolving coupled climate models from NOAA/GFDL.
- Russell, J. L. (2014, Fall). New Observationally-Based Metrics for the Analysis of Coupled Climate Model and Earth System Model Simulations of the Southern Ocean. AGU Fall Meeting. San Francisco, CA: AGU.More infoThe exchange of heat and carbon dioxide between the atmosphere and ocean are major controls on Earth’s climate under conditions of anthropogenic forcing. The Southern Ocean south of 30°S, occupying just over ¼ of the surface ocean area, accounts for a disproportionate share of the vertical exchange of properties between the deep and surface waters of the ocean and between the surface ocean and the atmosphere; thus this region can be disproportionately influential on the climate system. Despite the crucial role of the Southern Ocean in the climate system, understanding of the particular mechanisms involved remains inadequate, and the model studies underlying many of these results are highly controversial. As part of the overall goal of working toward reducing uncertainties in climate projections, we present an analysis using new data/model metrics based on a unified framework of theory, quantitative datasets, and numerical modeling. These new metrics quantify the mechanisms, processes, and tendencies relevant to the role of the Southern Ocean in climate.
- Russell, J. L. (2014, February). Projections Of The Ocean’s Role In Climate: Heat And Carbon Uptake By The Southern Ocean In CMIP5. Ocean Sciences Meeting 2014. Honolulu, HI: AGU.More infoThe Southern Ocean, occupying just over one quarter of the surface ocean area, accounts for a disproportionate share of the vertical exchange of properties between the deep and surface waters of the ocean and between the surface ocean and the atmosphere, so it has a disproportionate influence on the climate system. In climate change experiments, Southern Ocean heat and carbon fluxes and the three-dimensional circulation patterns make it a region where much of the future oceanic heat and carbon uptake takes place, although the magnitude of the uptake is one of the larger sources of uncertainty associated with the transient climate response, especially in the latest Earth System Models that explicitly simulate the carbon cycle. We will assess the uptake of heat and carbon by the Southern Ocean in these future simulations from the suite of CMIP5 Earth System Models.
- Russell, J. L. (2014, July). Joint U.S. CLIVAR/OCB working group update: Southern Ocean Heat and Carbon Uptake. Ocean Carbon & Biogeochemistry Summer Science Workshop. Woods Hole, MA: Ocean Carbon and Biogeochemistry.
- Russell, J. L. (2014, July). Southern Ocean Heat and Carbon Uptake. 2014 Pan-CLIVAR Meeting. The Hague, Netherlands: CLIVAR/World Climate Research Programme.
- Russell, J. L. (2014, September). Controls on the Latitudinal Distribution of Climate Processes: Results from Earth System Model Simulations. Hedberg Research Conferences. Banff, Alberta, Canada: American Association of Petroleum Geologists/Society for Sedimentary Geology.More infoThe main spatial variability of Earth’s climate in both the modern era and in the geologic record occurs with changes in latitude [Figure 1]. Solar insolation varies dramatically from the Equator to the poles, causing the main temperature bands to be primarily zonal (east-west). The dynamics of a spinning planet also cause the main wind belts, and therefore the main water delivery mechanisms to continental interiors, to be zonal as well. However, both the recent observational record and our paleoproxy evidence indicate that there have been changes in both the latitudinal extent of the Hadley Circulation and the mean position of the surface westerly wind belts in both hemispheres. These records also show that the main drivers of climate differences from the mean latitudinally-averaged climate are continentality, orography and ocean heat-transports, all of which can affect the zonal distribution of wet and dry zones. We can now test each of these major drivers in the new fully-coupled Earth System Models that include atmosphere, ocean, ice, land, vegetation and carbon dynamics.
- Russell, J. L. (2014, Septmeber). The Ocean's Role in Climate: Southern Ocean Heat and Carbon Uptake. Bolin Center for Climate Research, Stockholm University, Seminar. Stockholm, Sweden: Bolin Center for Climate Research, Stockholm University.
- Russell, J. L., & Kamenkovich, I. (2014, July). Southern Ocean Heat & Carbon Uptake. US CLIVAR Summit 2014. Denver, CO: US CLIVAR.More infoUpdate on progress of Southern Ocean Working Group
- Russell, J. L. (2013, Fall). Climate Modeling and GIS Integration for Biology and Breeding. Winter Breeding Institute. Tucson, AZ: iPlant Collaborative.
- Russell, J. L. (2013, Fall). How the Southern Ocean is Helping Arizona Keep Its Cool. Atmosphere and Oceanic Sciences, Princeton University. Princeton, NJ.
- Russell, J. L. (2013, Fall). Impact of Aerosol and Cloud Biases on Southern Ocean Carbon and Heat Uptake in CMIP5 Simulations. AGU. San Francisco, CA: American Geophysical Union.
- Russell, J. L. (2013, Fall). Southern Ocean Heat and Carbon Uptake. Ocean Carbon and Biogeochemistry Summer Workshop. Woods Hole, MA.
- Russell, J. L. (2013, Fall). The Southern Ocean’s Role in Global Climate, Meteorology and Physical Oceanography. Rosenstiel School of Marine and Atmospheric Science. Miami, FL.
- Russell, J. (2012, Fall). Carbon Feedback of Ocean Ventilation Changes in Past and Future Climates, Modes of Variability in the Climate System: Past-Present-Future. European Science Foundation. Obergurgl, Austria.
- Russell, J. L. (2012, Fall). Interactions Between Antarctic Winds, Ocean And Orography In An Earth System Model. AGU. San Francisco, CA: American Geophysical Union.
- Russell, J. L. (2012, Fall). The Ocean's Role in Climate: Southern Ocean Uptake of Heat and Carbon. Department of Geosciences, University of Arizona. Tucson, AZ.
- Russell, J. L., Delworth, T., Dixon, K., & Rosati, A. (2012, Fall). The Uptake And Storage Of Heat By The Southern Ocean In The GFDL CM2.5 High-Resolution Coupled Climate Model. Ocean Sciences Meeting. Salt Lake City, UT.
- Russell, J. L. (2018, Spring). Metrics for the Evaluation of the Southern Ocean in Coupled Climate Models and Earth System Models. 2018 Ocean Sciences Meeting. Portland, OR: American Geophysical Union.More infoGlobal coupled climate models and earth system models vary widely in their simulations of the Southern Ocean and its role in, and response to, the ongoing anthropogenic trend. New observations and understanding have allowed for progress in the creation of observationally-based data/model metrics for the Southern Ocean, especially with respect to uncertainties related to oceanic heat and carbon uptake. Metrics that compare simulations to new data, including that obtained from the Southern Ocean Carbon and Climate Observations project (SOCCOM) float array , and to new state estimates, like the Biogeochemical Southern Ocean State Estimate (B-SOSE), are critical for discerning processes and mechanisms, and for validating and comparing climate and earth system models. Models that quantitatively perform better against current observations will better simulate the future uptake of heat and carbon by the Southern Ocean. Here, we present observationally-based benchmarks that highlight differences and strengths and weaknesses due to model resolution, especially those related to oceanic heat and carbon uptake.
- Wanninkhof, R., Johnson, K., Williams, N., Sarmiento, J. L., Riser, S., Briggs, E., Bushinsky, S., Carter, B., Dickson, A., Feely, R. A., Gray, A., Juranek, L., Key, R., Talley, L., Russell, J. L., & Verdy, A. (2017, Spring). An evaluation of pH and NO3 sensor data from SOCCOM floats and their utilization to develop ocean inorganic carbon products. soccom.princeton.edu, CDIAC, NOAA. https://soccom.princeton.edu/content/soccom-publicationsMore infoA summary of discussions and recommendations of the Carbon Working Group (CWG) of the Southern Ocean Carbon and Climate Observations and Modeling project (SOCCOM)
- Group, B. P., & Russell, J. L. (2016, 2016). The scientific rationale, design and implementation plan for a Biogeochemical-Argo float array. http://biogeochemical-argo.org/cloud/document/science-implementation-plan/BGC-Argo_Science_Implementation_Plan.pdfMore infoThe extension of the Argo array of profiling floats to include biogeochemical sensors for pH, oxygen, nitrate, chlorophyll, suspended particles, and downwelling irradiance. These efforts culminated in a workshop that was held from 11 to 13 January 2016 at the Laboratoire d’Océanographie de Villefranche-sur-mer, France. This document is a summary of the discussions at the Villefranche workshop and has been reviewed by attendees. Review by the Argo Steering Team and community input have been solicited next.
- Russell, J. L., & Kamenkovich, I. (2015, Fall). Biogeochemical metrics for the evaluation of the Southern Ocean in Earth system models. Variations: A joint US CLIVAR & OCB Newsletter. http://usclivar.org/sites/default/files/documents/2015/Variations2015Fall_0.pdf
- Russell, J. L., & Kamenkovich, I. (2015, Fall). The Southern Ocean’s Role in Climate. Variations: A joint US CLIVAR & OCB Newsletter, 13(4), 32pp.. http://usclivar.org/sites/default/files/documents/2015/Variations2015Fall_0.pdf
- Russell, J. L., Benway, H., Bracco, A., Deutsch, C., Ito, T., Kamenkovich, I., & Patterson, M. (2015, Fall). Ocean’s Carbon and Heat Uptake: Uncertainties and Metrics. US CLIVAR Report 2015-3. https://usclivar.org/sites/default/files/documents/2015/SO-OCU-Workshop-Report-final_0.pdfMore infoWorkshop Report
- Russell, J. L., Sarmiento, J., Cullen, H., Johnson, K., RIser, S., & Talley, L. (2014, November). The Southern Ocean Carbon and Climate Observations and Modeling Program (SOCCOM). Ocean Carbon and Biogeochemistry News. http://us-ocb.org/publications/OCB_NEWS_FALL14.pdf