HomeCoursesDrought research in a changing climate

Drought research in a changing climate

Lectures

The lectures below are from a PhD-level drought seminar that Dr. Toby Ault gave at Stockholm University in the spring semester of 2022. The final tab is a list of curated references for further reading.

Lecture 1 presents an overview of key drought concepts while introducing key questions like, what is drought? How do we monitor and model it? What causes it? What does the future hold? And what are some interesting areas of future drought research?

PowerPoint Slides: MISU-Drought_Lecture_1

Lecture 2 takes a deeper look at some of the most widely used drought indices (e.g., indicators of relative surface moisture anomalies) including the PDSI, SPI, and SPEI. Characteristics of any generalized drought indicator are also discussed.

Lecture 3 examines the simplified physics and equations underlying so-called “leaky bucket” models of the surface soil moisture balance.
In Lecture 4 we look at more advanced models of soil moisture including those used in land data assimilation (e.g., NLDAS and GLDAS) products.
Lecture 5 presents an overview of the challenges, progress, and opportunities associated with measuring or observing soil moisture from remote sensing and in situ sensors.
Lecture 6 covers a few basic ideas about how the ocean (primarily El Niño and La Niña) affects drought.
In Lecture 7 we look back at the past millennium to help understand the “natural” range of drought variations that have occurred in western North America and other parts of the world.
Lecture 8 uses some of our own research at ECRL to show how higher temperatures in the future will likely make droughts and mega droughts more probable as this century unfolds. It also discusses ideas for extending the analyses we’ve done to other settings and other related phenomena.

Introduction & Background

  1. D. A. Herrera, T. R. Ault, J. T. Fasullo, S. J. Coats, C. M. Carrillo, B. I. Cook, and A. P. Williams, “Exacerbation of the 20132016 PanCaribbean Drought by Anthro- pogenic Warming,” Geophysical Research Letters, vol. 45, oct 2018.
  2. I. R. Tannehill, Drought: Its causes and consequences. Princeton, NJ: Princeton University Press, 1947.
  3. D. A. Wilhite, Chapter 1 Drought as a Natural Hazard: Concepts and Definitions. Lincoln, NE: Drought Mitigation Center Faculty Publications, 2000.
  4. A. B. Smith and J. L. Matthews, “Quantifying uncertainty and variable sensitivity within the US billion-dollar weather and climate disaster cost estimates,” Natural Hazards, vol. 77, pp. 1829–1851, jul 2015.
  5. B. M. Buckley, K. J. Anchukaitis, D. Penny, R. Fletcher, E. R. Cook, M. Sano, L. C. Nam, A. Wichienkeeo, T. T. Minh, and T. M. Hong, “Climate as a contributing factor in the demise of Angkor, Cambodia,” Proceedings of the National Academy of Sciences, vol. 107, pp. 6748–6752, apr 2010.
  6. N. P. Evans, T. K. Bauska, F. G ́azquez-S ́anchez, M. Brenner, J. H. Curtis, and D. A. Hodell, “Quantification of drought during the collapse of the classic Maya civilization,” Science, vol. 361, pp. 498–501, aug 2018.
  7. L. Benson, K. Petersen, and J. Stein, “Anasazi (Pre-Columbian Native-American) Migrations During The Middle-12Th and Late-13th Centuries Were they Drought Induced?,” Climatic Change, vol. 83, pp. 187–213, mar 2006.
  8. P. Zhang, H. Cheng, R. L. Edwards, F. Chen, Y. Wang, X. Yang, J. Liu, M. Tan, X. Wang, J. Liu, C. An, Z. Dai, J. Zhou, D. Zhang, J. Jia, L. Jin, and K. R. Johnson, “A test of climate, sun, and culture relationships from an 1810-year Chinese cave record,” Science, vol. 322, pp. 940–942, nov 2008.
  9. R. Seager, M. F. Ting, I. Held, Y. Kushnir, J. Lu, G. Vecchi, H. P. Huang, N. Harnik, A. Leetmaa, N. C. Lau, C. H. Li, J. Velez, and N. Naik, “Model projections of an imminent transition to a more arid climate in southwestern North America,” Science, vol. 316, no. 5828, pp. 1181–1184, 2007.
  10. A. Dai, “Increasing drought under global warming in observations and models,” NA- TURE CLIMATE CHANGE, vol. 3, pp. 52–58, jan 2013.
  11. B. I. Cook, J. E. Smerdon, R. Seager, and S. Coats, “Global warming and 21st century drying,” Climate Dynamics, vol. 43, pp. 2607–2627, mar 2014.
  12. B. I. Cook, T. R. Ault, and J. E. Smerdon, “Unprecedented 21st century drought risk in the American Southwest and Central Plains,” Science Advances, vol. 1, no. Febru- ary, pp. 1–7, 2015.
  13. J. E. Herrera-Estrada and J. Sheffield, “Uncertainties in future projections of summer droughts and heat waves over the contiguous United States,” Journal of Climate, vol. 30, pp. 6225–6246, aug 2017.
  14. T. R. Ault, J. Mankin, B. I. Cook, and J. E. Smerdon, “Relative impacts of mitigation, temperature, and precipitation on 21st-century megadrought risk in the American Southwest,” Science Advances, 2016.
  15. A. K. Mishra and V. P. Singh, “A review of drought concepts,” JOURNAL OF HY- DROLOGY, vol. 391, pp. 204–216, sep 2010.
  16. A. Dai, “Drought under global warming: a review,” Wiley Interdisciplinary Reviews: Climate Change, vol. 2, pp. 45–65, jan 2011.
  17. S. Mukherjee, A. Mishra, and K. E. Trenberth, “Climate Change and Drought: a Perspective on Drought Indices,” CURRENT CLIMATE CHANGE REPORTS, vol. 4, pp. 145–163, jun 2018.
  18. B. I. Cook, J. S. Mankin, and K. J. Anchukaitis, “Climate Change and Drought: From Past to Future,” jun 2018.
  19. K. T. Redmond, “The depiction of drought – A commentary,” Bulletin of the American Meteorological Society, vol. 83, no. 8, pp. 1143–1147, 2002.
  20. C. A. Woodhouse and J. T. Overpeck, “2000 years of drought variability in the cen- tral United States,” Bulletin of the American Meteorological Society, vol. 79, no. 12, pp. 2693–2714, 1998.
  21. J. Huang, H. M. VandenDool, and K. P. Georgakakos, “Analysis of model-calculated soil moisture over the United States (1931-1993) and applications to long-range tem- perature forecasts,” Journal of Climate, vol. 9, pp. 1350–1362, jun 1996.
  22. T. J. Osborn and P. D. Jones, “The CRUTEM4 land-surface air temperature data set: construction, previous versions and dissemination via Google Earth,” Earth System Science Data, vol. 6, pp. 61–68, feb 2014.
  23. N. J. L. Lenssen, G. A. Schmidt, J. E. Hansen, M. J. Menne, A. Persin, R. Ruedy, and D. Zyss, “Improvements in the GISTEMP Uncertainty Model,” Journal of Geophysical Research: Atmospheres, vol. 124, pp. 6307–6326, jun 2019.
  24. A. Dai and T. Zhao, “Uncertainties in historical changes and future projections of drought. Part I: estimates of historical drought changes,” CLIMATIC CHANGE, vol. 144, pp. 519–533, oct 2017.
  25. A. Dai, T. Qian, K. E. Trenberth, and J. D. Milliman, “Changes in Continental Freshwater Discharge from 1948 to 2004,” Journal of Climate, vol. 22, pp. 2773–2792, may 2009.

Drought Indices

  1. W. C. Palmer, “Meteorological drought,” 1965.
  2. N. Wells, S. Goddard, and M. J. Hayes, “A self-calibrating Palmer Drought Severity Index,” Journal of Climate, vol. 17, no. 12, pp. 2335–2351, 2004.
  3. S. M. Vicente-Serrano, S. Beguer ́ıa, and J. I. L ́opez-Moreno, “A multiscalar drought index sensitive to global warming: The standardized precipitation evapotranspiration index,” J. Clim., vol. 23, no. 7, pp. 1696–1718, 2010.
  4. Z. Hao and A. AghaKouchak, “Multivariate Standardized Drought Index: A paramet- ric multi-index model,” Advances in Water Resources, vol. 57, pp. 12–18, jul 2013.
  5. N. B. Guttman, “Accepting the standardized precipitation index: A calculation algo- rithm,” Journal of the American Water Resources Association, vol. 35, no. 2, pp. 311– 322, 1999.
  6. W. M. Alley, “The Palmer Drought Severity Index – Limitations and Assumptions,” Journal of Climate and Applied Meteorology, vol. 23, no. 7, pp. 1100–1109, 1984.
  7. T. B. McKee, N. J. Doeskin, and J. Kleist, “The Relationship of Drought Frequency and Duration to Time Scales,” Proc. 8th Conf. on Aplied Climatology, pp. 179–184, jan 1993.
  8. R. G. Allen, L. S. Pereira, D. Raes, and M. Smith, “Crop evapotranspiration- Guidelines for computing crop water requirements-FAO Irrigation and drainage paper 56,” tech. rep., 1998.
  9. E. Kalnay, M. Kanamitsu, R. Kistler, W. Collins, D. Deaven, L. Gandin, M. Iredell, S. Saha, G. White, J. Woollen, Y. Zhu, M. Chelliah, W. Ebisuzaki, W. Higgins, J. Janowiak, K. C. Mo, C. Ropelewski, J. Wang, A. Leetmaa, R. Reynolds, R. Jenne, and D. Joseph, “The NCEP/NCAR 40-year reanalysis project,” Bulletin of the Amer- ican Meteorological Society, vol. 77, no. 3, pp. 437–471, 1996.
  10. K. E. Trenberth, A. Dai, G. van der Schrier, P. D. Jones, J. Barichivich, K. R. Briffa, and J. Sheffield, “Global warming and changes in drought,” NATURE CLIMATE CHANGE, vol. 4, pp. 17–22, jan 2014.
  11. A. Dai, “Characteristics and trends in various forms of the Palmer Drought Severity Index during 19002008,” Journal of Geophysical Research, vol. 116, p. D12115, jun 2011.
  12. A. Dai, K. E. Trenberth, and T. T. Qian, “A global dataset of Palmer Drought Severity Index for 1870-2002: Relationship with soil moisture and effects of surface warming,” Journal of Hydrometeorology, vol. 5, pp. 1117–1130, dec 2004.
  13. B. I. Cook, J. E. Smerdon, R. Seager, and S. Coats, “Global warming and 21 st century drying,” Climate Dynamics, vol. 43, no. 9-10, pp. 2607–2627, 2014.
  14. J. E. Smerdon, B. I. Cook, E. R. Cook, and R. Seager, “Bridging Past and Future Climate across Paleoclimatic Reconstructions, Observations, and Models: A Hydro- climate Case Study*,” Journal of Climate, vol. 28, pp. 3212–3231, apr 2015.
  15. G. van der Schrier, J. Barichivich, K. R. Briffa, and P. D. Jones, “A scPDSI-based global data set of dry and wet spells for 1901-2009,” JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, vol. 118, pp. 4025–4048, may 2013.

Models of Soil Moisture

  1. Y. Fan and H. van den Dool, “Climate Prediction Center global monthly soil moisture data set at 0.5 degrees resolution for 1948 to present,” JOURNAL OF GEOPHYSI- CAL RESEARCH-ATMOSPHERES, vol. 109, may 2004.
  2. J. Sheffield, G. Goteti, and E. F. Wood, “Development of a 50-Year High-Resolution Global Dataset of Meteorological Forcings for Land Surface Modeling,” Journal of Climate, vol. 19, no. 13, pp. 3088–3111, 2006.
  3. K. E. Mitchell, D. Lohmann, P. R. Houser, E. F. Wood, J. C. Schaake, A. Robock, B. A. Cosgrove, J. Sheffield, Q. Duan, L. Luo, R. W. Higgins, R. T. Pinker, J. D. Tarpley, D. P. Lettenmaier, C. H. Marshall, J. K. Entin, M. Pan, W. Shi, V. Koren, J. Meng, B. H. Ramsay, and A. A. Bailey, “The multi-institution North American Land Data Assimilation System (NLDAS): Utilizing multiple GCIP products and partners in a continental distributed hydrological modeling system,” Journal of Geophysical Research D: Atmospheres, vol. 109, apr 2004.
  4. M. Rodell, P. R. Houser, U. Jambor, J. Gottschalck, K. Mitchell, C. J. Meng, K. Arsenault, B. Cosgrove, J. Radakovich, M. Bosilovich, J. K. Entin, J. P. Walker, D. Lohmann, and D. Toll, “The Global Land Data Assimilation System,” Bulletin of the American Meteorological Society, vol. 85, pp. 381–394, mar 2004.
  5. J.Sheffieldand E.F.Wood,“Global Trends And Variability In Soil Moisture And Drought characteristics, 1950-2000, from observation-driven Simulations of the terrestrial hy- drologic cycle,” Journal of Climate, vol. 21, no. 3, pp. 432–458, 2008.
  6. A. Dai, T. Zhao, and J. Chen, “Climate Change and Drought: a Precipitation and Evaporation Perspective,” CURRENT CLIMATE CHANGE REPORTS, vol. 4, pp. 301–312, sep 2018.
  7. Measuring Soil Moisture
  8. W. A. Dorigo, W. Wagner, R. Hohensinn, S. Hahn, C. Paulik, A. Xaver, A. Gruber, M. Drusch, S. Mecklenburg, P. Van Oevelen, A. Robock, and T. Jackson, “Hydrology and Earth System Sciences The International Soil Moisture Network: a data hosting facility for global in situ soil moisture measurements,” Hydrol. Earth Syst. Sci, vol. 15, pp. 1675–1698, 2011.
  9. D. Entekhabi, E. G. Njoku, P. E. O’Neill, K. H. Kellogg, W. T. Crow, W. N. Edelstein, J. K. Entin, S. D. Goodman, T. J. Jackson, J. Johnson, J. Kimball, J. R. Piepmeier, R. D. Koster, N. Martin, K. C. McDonald, M. Moghaddam, S. Moran, R. Reichle, J. C. Shi, M. W. Spencer, S. W. Thurman, L. Tsang, and J. Van Zyl, “The Soil Moisture Active Passive (SMAP) Mission,” PROCEEDINGS OF THE IEEE, vol. 98, pp. 704–716, may 2010.

Drought Dynamics

  1. A. Dai and T. M. L. Wigley, “Global patterns of ENSO-induced precipitation,” Geo- physical Research Letters, vol. 27, pp. 1283–1286, may 2000.
  2. K. E. Trenberth, J. Fasullo, and L. Smith, “Trends and variability in column-integrated atmospheric water vapor,” Climate Dynamics, vol. 24, pp. 741–758, jun 2005.
  3. S. Philander, El Nino, La Nina, and the Southern Oscillation, Volume 46. Academic Press, 1990.
  4. K. E. Trenberth, G. W. Branstator, D. Karoly, A. Kumar, N. C. Lau, and C. Ro- pelewski, “Progress during TOGA in understanding and modeling global telecon- nections associated with tropical sea surface temperatures,” Journal of Geophysical Research-Oceans, vol. 103, pp. 14291–14324, jun 1998.
  5. M. A. Alexander, I. Blade, M. Newman, J. R. Lanzante, N. C. Lau, and J. D. Scott, “The atmospheric bridge: The influence of ENSO teleconnections on air-sea interac- tion over the global oceans,” Journal of Climate, vol. 15, pp. 2205–2231, aug 2002.
  6. J.-H. Qian, A. W. Robertson, and V. Moron, “Interactions among ENSO, the Mon- soon, and Diurnal Cycle in Rainfall Variability over Java, Indonesia,” Journal of the Atmospheric Sciences, vol. 67, pp. 3509–3524, nov 2010.
  7. N. Zeng, A. Mariotti, and P. Wetzel, “Terrestrial mechanisms of interannual CO 2 variability,” Global Biogeochemical Cycles, vol. 19, mar 2005.
  8. C. F. Ropelewski and M. S. Halpert, “North American Precipitation and Tempera- ture Patterns Associated with the El Nin ̃o/Southern Oscillation (ENSO),” Monthly Weather Review, vol. 114, pp. 2352–2362, dec 1986.
  9. R. Seager, N. Naik, M. Ting, M. A. Cane, N. Harnik, and Y. Kushnir, “Adjustment of the atmospheric circulation to tropical Pacific SST anomalies: Variability of transient eddy propagation in the Pacific-North America sector,” Quarterly Journal of the Royal Meteorological Society, vol. 136, pp. 277–296, jan 2010.
  10. M. P. Hoerling and Mingfang Ting, “Organization of extratropical transients during El Nino,” Journal of Climate, vol. 7, no. 5, pp. 745–766, 1994.
  11. J. W. Hurrell, “Decadal trends in the North Atlantic oscillation: Regional tempera- tures and precipitation,” Science, vol. 269, no. 5224, pp. 676–679, 1995.
  12. J. I. L ́opez-Moreno and S. M. Vicente-Serrano, “Positive and Negative Phases of the Wintertime North Atlantic Oscillation and Drought Occurrence over Europe: A Multitemporal-Scale Approach,” Journal of Climate, vol. 21, pp. 1220–1243, mar 2008.
  13. K. E. TRENBERTH and C. J. GUILLEMOT, “EVALUATION OF THE GLOBAL ATMOSPHERIC MOISTURE BUDGET AS SEEN FROM ANALYSES,” Journal of Climate, vol. 8, pp. 2255–2272, sep 1995.
  14. R. Seager, N. Harnik, W. A. Robinson, Y. Kushnir, M. Ting, H. P. Huang, and J. Velez, “Mechanisms of ENSO-forcing of hemispherically symmetric precipitation variability,” Quarterly Journal of the Royal Meteorological Society, vol. 131, pp. 1501–1527, apr 2005.
  15. J. Bjerknes, “Atmospheric teleconnections from the equatorial Pacific,” Monthly Weather Review, vol. 97, no. 3, pp. 163–172, 1969.

Drought During Climate Change

  1. R. Seager, N. Naik, and G. A. Vecchi, “Thermodynamic and Dynamic Mechanisms for Large-Scale Changes in the Hydrological Cycle in Response to Global Warming,” Journal of Climate, vol. 23, pp. 4651–4668, sep 2010.
  2. A. Seth, S. A. Rauscher, M. Biasutti, A. Giannini, S. J. Camargo, and M. Rojas, “CMIP5 Projected Changes in the Annual Cycle of Precipitation in Monsoon Re- gions,” Journal of Climate, vol. 26, pp. 7328–7351, oct 2013.
  3. J. Sheffield and E. F. Wood, “Projected changes in drought occurrence under future global warming from multi-model, multi-scenario, IPCC AR4 simulations,” Climate Dynamics, vol. 31, pp. 79–105, jul 2008.
  4. A. Dai, “Drought under global warming: a review,” Wiley Interdisciplinary Reviews- Climate Change, vol. 2, no. 1, pp. 45–65, 2011.
  5. J. Sheffield, E. F. Wood, and M. L. Roderick, “Little change in global drought over the past 60 years,” Nature, vol. 491, pp. 435+, nov 2012.
  6. P. Greve, B. Orlowsky, B. Mueller, J. Sheffield, M. Reichstein, and S. I. Seneviratne, “Global assessment of trends in wetting and drying over land,” NATURE GEO- SCIENCE, vol. 7, pp. 716–721, oct 2014.
  7. K. B. Karnauskas, J. P. Donnelly, and K. J. Anchukaitis, “Future freshwater stress for island populations,” Nature Clim. Change, vol. advance on, apr 2016.
  8. A. Berg and J. Sheffield, “Climate Change and Drought: the Soil Moisture Perspec- tive,” CURRENT CLIMATE CHANGE REPORTS, vol. 4, pp. 180–191, jun 2018.
  9. B. I. Cook, E. R. Cook, J. E. Smerdon, R. Seager, A. P. Williams, S. Coats, D. W. Stahle, and J. V. D ́ıaz, “North American megadroughts in the Common Era: recon- structions and simulations,” Wiley Interdisciplinary Reviews: Climate Change, vol. 7, pp. 411–432, mar 2016.
  10. J. Smerdon, J. Luterbacher, S. Phipps, K. Anchukaitis, T. Ault, S. Coats, K. Cobb, B. Cook, C. Colose, T. Felis, A. Gallant, J. Jungclaus, B. Konecky, A. LeGrande, S. Lewis, A. Lopatka, W. Man, J. Mankin, J. Maxwell, B. Otto-Bliesner, J. Partin, D. Singh, N. Steiger, J. Tierney, D. Zanchettin, H. Zhang, A. Atwood, L. Andreu- Hayles, S. Baek, B. Buckley, E. Cook, R. D’Arrigo, S. Dee, M. Griffiths, C. Kulkarni, Y. Kushnir, F. Lehner, C. Leland, A. Okazaki, J. Palmer, E. Piovano, C. Raible, M. Rao, J. Scheff, G. Schmidt, R. Seager, M. Widmann, J. Scheff, and E. Xoplaki, “Comparing proxy and model estimates of hydroclimate variability and change over the Common Era,” Climate of the Past, vol. 13, no. 12, 2017.
  11. K. Marvel, B. I. Cook, C. J. Bonfils, P. J. Durack, J. E. Smerdon, and A. P. Williams, “Twentieth-century hydroclimate changes consistent with human influence,” Nature, vol. 569, pp. 59–65, may 2019.

Unresolved Questions

  1. P. C. Milly and K. A. Dunne, “Potential evapotranspiration and continental drying,” Nature Climate Change, vol. 6, pp. 946–949, sep 2016.
  2. A. L. S. Swann, F. M. Hoffman, C. D. Koven, and J. T. Randerson, “Plant responses to increasing CO2 reduce estimates of climate impacts on drought severity,” Proceedings of the National Academy of Sciences, 2016.
  3. B. Mueller and S. I. Seneviratne, “Systematic land climate and evapotranspiration biases in CMIP5 simulations,” Geophysical Research Letters, vol. 41, pp. 128–134, jan 2014.
  4. I. M. Held and B. J. Soden, “Robust responses of the hydrological cycle to global warming,” Journal of Climate, vol. 19, pp. 5686–5699, nov 2006.
  5. G. T. Walker and E. W. Bliss, “World Weather V,” Memoirs of the Royal Meteoro- logical Society, vol. 4, no. 36, pp. 53–84, 1932.
  6. G. a. Vecchi, B. J. Soden, A. T. Wittenberg, I. M. Held, A. Leetmaa, and M. J. Harrison, “Weakening of tropical Pacific atmospheric circulation due to anthropogenic forcing.,” Nature, vol. 441, pp. 73–6, may 2006.
  7. G. a. Vecchi and B. J. Soden, “Global Warming and the Weakening of the Tropical Circulation,” Journal of Climate, vol. 20, pp. 4316–4340, sep 2007.
  8. M. L. L’Heureux, S. Lee, and B. Lyon, “Recent multidecadal strengthening of the Walker circulation across the tropical Pacific,” Nature Climate Change, vol. 3, pp. 571– 576, mar 2013.
  9. E. S. Chung, A. Timmermann, B. J. Soden, K. J. Ha, L. Shi, and V. O. John, “Rec- onciling opposing Walker circulation trends in observations and model projections,” Nature Climate Change, vol. 9, pp. 405–412, may 2019.
  10. R. Seager, M. Cane, N. Henderson, D. E. Lee, R. Abernathey, and H. Zhang, “Strengthening tropical Pacific zonal sea surface temperature gradient consistent with rising greenhouse gases,” jul 2019.
  11. B. C. O’Neill, J. M. Done, A. Gettelman, P. Lawrence, F. Lehner, J. F. Lamarque, L. Lin, A. J. Monaghan, K. Oleson, X. Ren, B. M. Sanderson, C. Tebaldi, M. Weitzel, Y. Xu, B. Anderson, M. J. Fix, and S. Levis, “The Benefits of Reduced Anthropogenic Climate changE (BRACE): a synthesis,” Climatic Change, vol. 146, pp. 287–301, feb 2018.

Future Work

  1. F. Lehner, S. Coats, T. F. Stocker, A. G. Pendergrass, B. M. Sanderson, C. C. Raible, and J. E. Smerdon, “Projected drought risk in 1.5C and 2C warmer climates,” Geo- physical Research Letters, vol. 44, pp. 7419–7428, jul 2017.
  2. M. A. Taylor, L. A. Clarke, A. Centella, A. Bezanilla, T. S. Stephenson, J. J. Jones, J. D. Campbell, A. Vichot, and J. Charlery, “Future Caribbean Climates in a World of Rising Temperatures: The 1.5 vs 2.0 Dilemma,” JOURNAL OF CLIMATE, vol. 31, pp. 2907–2926, apr 2018.
  3. J. S. Mankin, J. E. Smerdon, B. I. Cook, A. P. Williams, and R. Seager, “The Curious Case of Projected Twenty-First-Century Drying but Greening in the American West,” Journal of Climate, vol. 30, pp. 8689–8710, nov 2017.
  4. J. E. Kay, C. Deser, A. Phillips, A. Mai, C. Hannay, G. Strand, J. M. Arblaster, S. C. Bates, G. Danabasoglu, J. Edwards, M. Holland, P. Kushner, J.-F. Lamarque, D. Lawrence, K. Lindsay, A. Middleton, E. Munoz, R. Neale, K. Oleson, L. Polvani, and M. Vertenstein, “The Community Earth System Model (CESM) Large Ensem- ble Project: A Community Resource for Studying Climate Change in the Presence of Internal Climate Variability,” Bulletin of the American Meteorological Society, p. 141119125353005, nov 2014.