Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder

Kris Karnauskas

Research Interests

My lab explores the dynamics of the coupled Earth system toward useful predictions of impacts ranging from marine ecosystems to human health. Specifically, we aim to understand the circuitry of the tropical ocean and atmosphere, its interaction with ecosystems and with higher latitude regions, how and why the climate system has changed in the past, and how climate will continue to change in the future–both naturally and as driven by human activities. We employ a "big data" methodology, leveraging satellite and instrumental observations, large international ensembles of global coupled climate model simulations, and running several ocean and atmosphere circulation models in house.

Teaching Profile

Through teaching, I aim to equip students with the tools to investigate, communicate, and act intelligently on matters of global change. I routinely teach courses on climate science and oceanography (ATOC 1060, ATOC 3070, ATOC 4730/5730).

Current Research

Climate Dynamics:

One of my primary research objectives is to understand the dynamics of Earth's climate at global and regional scales. How and why does climate vary from year to year, decade to decade, century to century, and beyond? A particular focus is on the dynamics of the tropical ocean and atmosphere as a coupled system, such as the El Nino-Southern Oscillation (ENSO) and other intrinsic modes of climate variability. How do the tropics, extratropics, and high latitude regions interact? How will key aspects of Earth's climate respond to the radiative forcing associated with greenhouse gas emissions over the course of this century? I use observations (including satellites) and numerical models to explore these questions.

Climate Impacts:

"No challenge poses a greater threat to future generations than climate change," said President Barack Obama in his State of the Union address on January 20, 2015. Climate change is a global problem, but the impacts are felt locally. "...rising oceans, longer, hotter heat waves, dangerous droughts and floods, and massive disruptions that can trigger greater migration and conflict and hunger around the globe. The Pentagon says that climate change poses immediate risks to our national security. We should act like it."

In my lab, we combine "big data" (dozens of global climate models, satellites, etc.) as well as pinpoint measurements to understand the impacts of climate variability and change on marine ecosystems, transportation, freshwater resources, sea level, and tropical cyclones.

Ocean Circulation:

The thermal inertial of the climate system is in the ocean, so understanding the physics governing the storage of heat by the ocean and the movement of heat and other properties by currents is essential to understanding climate variability and change. Ocean circulation also serves as the mediator between large-scale climate variability and impacts on marine ecosystems. I seek to better understand the ocean circulation, particularly in the tropical Pacific, and translate such knowledge into improved overall understanding of global climate dynamics and projected impacts on marine ecosystems.  


Hadley circulation. A side view depicting the familiar atmospheric overturning cell linking Earth's tropics and subtropics. In "On the dynamics of the Hadley circulation and subtropical drying," we (Karnauskas and Ummenhofer 2014) argue that this perspective hides some of the basic, underlying dynamics and spatial structure of the Hadley circulation.


Freshwater stress. At least 18 million people live on islands too small for the current generation of global climate models (GCMs) to resolve. Efforts are afoot to characterize the freshwater balance and its likely response to global warming at such places anyway.

The Galápagos Islands and the Equatorial Undercurrent. Viewed from space, the Galápagos is but a dot in an otherwise enormous basin. However, the very dynamics governing the equatorial oceans also confer upon the Galápagos a potential influence significantly beyond that expected from its physical dimensions (Karnauskas et al. 2007).

Honors and Awards

  • AGU Ocean Sciences Early Career Award
  • Sloan Research Fellowship, Alfred P. Sloan Foundation
  • Moltz Fellowship, Ocean and Climate Change Institute, WHOI
  • Lamont Postdoctoral Fellowship, LDEO of Columbia University
  • Meteorological Satellite Applications Award, National Weather Association
  • Hilldale Undergraduate Research Fellowship, University of Wisconsin-Madison

View Publications

  • Bryan, SP; Hughen, KA; Karnauskas, KB; Farrar, JT (2019), Two Hundred Fifty Years of Reconstructed South Asian Summer Monsoon Intensity and Decadal-Scale Variability. Version: 1 GEOPHYSICAL RESEARCH LETTERS 46 (7) 3927-3935, issn: 0094-8276, doi: 10.1029/2018GL081593
  • Goodkin, NF; Bolton, A; Hughen, KA; Karnauskas, KB; Griffin, S; Phan, KH; Vo, ST; Ong, MR; Druffel, ERM (2019), East Asian Monsoon Variability Since the Sixteenth Century. Version: 1 GEOPHYSICAL RESEARCH LETTERS 46 (9) 4790-4798, issn: 0094-8276, doi: 10.1029/2019GL081939
  • Hamlington, BD; Cheon, SH; Piecuch, CG; Karnauskas, KB; Thompson, PR; Kim, KY; Reager, JT; Landerer, FW; Frederikse, T (2019), The Dominant Global Modes of Recent Internal Sea Level Variability. Version: 1 JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS 124 (4) 2750-2768, issn: 2169-9275, doi: 10.1029/2018JC014635
  • Samanta, D; Karnauskas, KB; Goodkin, NF (2019), Tropical Pacific SST and ITCZ Biases in Climate Models: Double Trouble for Future Rainfall Projections?. Version: 1 GEOPHYSICAL RESEARCH LETTERS 46 (4) 2242-2252, issn: 0094-8276, doi: 10.1029/2018GL081363
  • Zhang, L; Sun, DZ; Karnauskas, KB (2019), The role of the Indian Ocean in determining the tropical pacific SST response to radiative forcing in an idealized model. Version: 1 DYNAMICS OF ATMOSPHERES AND OCEANS 86 1-9, issn: 0377-0265, doi: 10.1016/j.dynatmoce.2019.02.003
  • Staten, PW; Grise, KM; Davis, SM; Karnauskas, K; Davis, N (2019), Regional Widening of Tropical Overturning: Forced Change, Natural Variability, and Recent Trends. Version: 1 JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 124 (12) 6104-6119, issn: 2169-897X, doi: 10.1029/2018JD030100
  • Zhang, L; Han, WQ; Karnauskas, KB; Meehl, GA; Hu, AX; Rosenbloom, N; Shinoda, T (2019), Indian Ocean Warming Trend Reduces Pacific Warming Response to Anthropogenic Greenhouse Gases: An Interbasin Thermostat Mechanism. Version: 1 GEOPHYSICAL RESEARCH LETTERS 46 (19) 10882-10890, issn: 0094-8276, doi: 10.1029/2019GL084088
  • Grise, KM; Davis, SM; Simpson, IR; Waugh, DW; Fu, Q; Allen, RJ; Rosenlof, KH; Ummenhofer, CC; Karnauskas, KB; Maycock, AC; Quan, XW; Birner, T; Staten, PW (2019), Recent Tropical Expansion: Natural Variability or Forced Response?. Version: 1 JOURNAL OF CLIMATE 32 (5) 1551-1571, issn: 0894-8755, doi: 10.1175/JCLI-D-18-0444.1
  • Lemmon, DE; Karnauskas, KB (2019), A metric for quantifying El Nino pattern diversity with implications for ENSO-mean state interaction. Version: 1 CLIMATE DYNAMICS 52 (12) 7511-7523, issn: 0930-7575, doi: 10.1007/s00382-018-4194-3
  • Zhang, L, KB Karnauskas, JB Weiss and LM Polvani (2018), Observational evidence of the downstream impact on tropical rainfall from stratospheric Kelvin waves. Clim. Dyn. Version: 1 50 (10-Sep) 3775-3782, issn: 0930-7575, ids: GC2YM, doi: 10.1007/s00382-017-3844-1
  • Maroon, EA, JE Kay and KB Karnauskas (2018), Influence of the Atlantic Meridional Overturning Circulation on the Northern Hemisphere Surface Temperature Response to Radiative Forcing. J. Clim. Version: 1 31 (22) 9207-9224, issn: 0894-8755, ids: GX3FY, doi: 10.1175/JCLI-D-17-0900.1
  • Karnauskas, KB, JK Lundquist and L Zhang (2018), Southward shift of the global wind energy resource under high carbon dioxide emissions. Nat. Geosci. Version: 1 11 (1) 38-+, issn: 1752-0894, ids: FU4SD, doi: 10.1038/s41561-017-0029-9
  • Coats, S and KB Karnauskas (2018), A Role for the Equatorial Undercurrent in the Ocean Dynamical Thermostat. J. Clim. Version: 1 31 (16) 6245-6261, issn: 0894-8755, ids: GM5OP, doi: 10.1175/JCLI-D-17-0513.1
  • Karnauskas, KB and BH Jones (2018), The Interannual Variability of Sea Surface Temperature in the Red Sea From 35 Years of Satellite and In Situ Observations. J. Geophys. Res.-Oceans Version: 1 123 (8) 5824-5841, issn: 2169-9275, ids: GU3OM, doi: 10.1029/2017JC013320
  • Samanta, D, KB Karnauskas, NF Goodkin, S Coats, JE Smerdon and L Zhang (2018), Coupled Model Biases Breed Spurious Low-Frequency Variability in the Tropical Pacific Ocean. Geophys. Res. Lett. Version: 1 45 (19) 10609-10618, issn: 0094-8276, ids: GY5XJ, doi: 10.1029/2018GL079455
  • Karnauskas, KB, CF Schleussner, JP Donnelly and KJ Anchukaitis (2018), Freshwater stress on small island developing states: population projections and aridity changes at 1.5 and 2 degrees C. Reg. Envir. Chang. Version: 1 18 (8) 2273-2282, issn: 1436-3798, ids: HA8VS, doi: 10.1007/s10113-018-1331-9
  • Karnauskas, KB, GC Johnson and R Murtugudde (2017), On the climate impacts of atolls in the central equatorial Pacific. Int. J. Climatol. Version: 1 37 (1) 197-203, issn: 0899-8418, ids: EI3TY, doi: 10.1002/joc.4697
  • Zhang, L and KB Karnauskas (2017), The Role of Tropical Interbasin SST Gradients in Forcing Walker Circulation Trends. J. Clim. Version: 1 30 (2) 499-508, issn: 0894-8755, ids: EH6BC, doi: 10.1175/JCLI-D-16-0349.1
  • Karnauskas, KB, E Mittelstaedt and R Murtugudde (2017), Paleoceanography of the eastern equatorial Pacific over the past 4 million years and the geologic origins of modern Galapagos upwelling. Earth Planet. Sci. Lett. Version: 1 460 22-28, issn: 0012-821X, ids: EJ1ZF, doi: 10.1016/j.epsl.2016.12.005
  • Zhang, L, KB Karnauskas, JP Donnelly and K Emanuel (2017), Response of the North Pacific Tropical Cyclone Climatology to Global Warming: Application of Dynamical Downscaling to CMIP5 Models. J. Clim. Version: 1 30 (4) 1233-1243, issn: 0894-8755, ids: EM7WG, doi: 10.1175/JCLI-D-16-0496.1
  • Zhang, L, T Rechtman, KB Karnauskas, LF Li, JP Donnelly and JP Kossin (2017), Longwave emission trends over Africa and implications for Atlantic hurricanes. Geophys. Res. Lett. Version: 1 44 (17) 9075-9083, Art. No. GL073869, issn: 0094-8276, ids: FI1OC, doi: 10.1002/2017GL073869
  • Coats, S and KB Karnauskas (2017), Are Simulated and Observed Twentieth Century Tropical Pacific Sea Surface Temperature Trends Significant Relative to Internal Variability?. Geophys. Res. Lett. Version: 1 44 (19) 9928-9937, issn: 0094-8276, ids: FL0SO, doi: 10.1002/2017GL074622
  • Hamlington, BD, JT Reager, MH Lo, KB Karnauskas and RR Leben (2017), Separating decadal global water cycle variability from sea level rise. Sci Rep Version: 1 7 , Art. No. 995, issn: 2045-2322, ids: ES6XO, doi: 10.1038/s41598-017-00875-5, PubMed ID: 28428539
  • Kendall, MS, M Poti and KB Karnauskas (2016), Climate change and larval transport in the ocean: fractional effects from physical and physiological factors. Glob. Change Biol. Version: 1 22 (4) 1532-1547, issn: 1354-1013, ids: DF7CN, doi: 10.1111/gcb.13159, PubMed ID: 26554877
  • DeCarlo, TM, KB Karnauskas, KA Davis and GTF Wong (2015), Climate modulates internal wave activity in the Northern South China Sea. Geophys. Res. Lett. Version: 1 42 (3) 831-838, issn: 0094-8276, ids: CD8OT, doi: 10.1002/2014GL062522
  • Capotondi, A, AT Wittenberg, M Newman, E Di Lorenzo, JY Yu, P Braconnot, J Cole, B Dewitte, B Giese, E Guilyardi, FF Jin, K Karnauskas, B Kirtman, T Lee, N Schneider, Y Xue and SW Yeh (2015), Understanding ENSO Diversity. Bull. Amer. Meteorol. Soc. Version: 1 96 (6) 921-938, issn: 0003-0007, ids: CN1WZ, doi: 10.1175/BAMS-D-13-00117.1
  • Karnauskas, KB, S Jenouvrier, CW Brown and R Murtugudde (2015), Strong sea surface cooling in the eastern equatorial Pacific and implications for Galapagos Penguin conservation. Geophys. Res. Lett. Version: 1 42 (15) 6432-6437, issn: 0094-8276, ids: CQ2FM, doi: 10.1002/2015GL064456
  • Karnauskas, KB, JP Donnelly, HC Barkley and JE Martin (2015), Coupling between air travel and climate. Nat. Clim. Chang. Version: 1 5 (12) 1068-1073, issn: 1758-678X, ids: CY4UA, doi: 10.1038/NCLIMATE2715
  • Trusel, LD, KE Frey, SB Das, KB Karnauskas, PK Munneke, E van Meijgaard and MR van den Broeke (2015), Divergent trajectories of Antarctic surface melt under two twenty-first-century climate scenarios. Nat. Geosci. Version: 1 8 (12) 927-U56, issn: 1752-0894, ids: CZ6GW, doi: 10.1038/NGEO2563
  • Maloney, ED, SJ Camargo, E Chang, B Colle, R Fu, KL Geil, Q Hu, XA Jiang, N Johnson, KB Karnauskas, J Kinter, B Kirtman, S Kumar, B Langenbrunner, K Lombardo, LN Long, A Mariotti, JE Meyerson, KC Mo, JD Neelin, ZT Pan, R Seager, Y Serra, A Seth, J Sheffield, J Stroeve, J Thibeault, SP Xie, CZ Wang, B Wyman and M Zhao (2014), North American Climate in CMIP5 Experiments: Part III: Assessment of Twenty-First-Century Projections*. J. Clim. Version: 1 27 (6) 2230-2270, issn: 0894-8755, ids: AC7CO, doi: 10.1175/JCLI-D-13-00273.1
  • Criscitiello, AS, SB Das, KB Karnauskas, MJ Evans, KE Frey, I Joughin, EJ Steig, JR McConnell and B Medley (2014), Tropical Pacific Influence on the Source and Transport of Marine Aerosols to West Antarctica. J. Clim. Version: 1 27 (3) 1343-1363, issn: 0894-8755, ids: 294YY, doi: 10.1175/JCLI-D-13-00148.1
  • Drenkard, EJ and KB Karnauskas (2014), Strengthening of the Pacific Equatorial Undercurrent in the SODA Reanalysis: Mechanisms, Ocean Dynamics, and Implications. J. Clim. Version: 1 27 (6) 2405-2416, issn: 0894-8755, ids: AC7CO, doi: 10.1175/JCLI-D-13-00359.1
  • Karnauskas, KB and CC Ummenhofer (2014), On the dynamics of the Hadley circulation and subtropical drying. Clim. Dyn. Version: 1 42 (10-Sep) 2259-2269, issn: 0930-7575, ids: AI6KW, doi: 10.1007/s00382-014-2129-1
  • Karnauskas, KB (2014), Arctic forcing of decadal variability in the tropical Pacific Ocean in a high-resolution global coupled GCM. Clim. Dyn. Version: 1 42 (12-Nov) 3375-3388, issn: 0930-7575, ids: AI6KX, doi: 10.1007/s00382-013-1836-3
  • Newby, PE, BN Shuman, JP Donnelly, KB Karnauskas and J Marsicek (2014), Centennial-to-millennial hydrologic trends and variability along the North Atlantic Coast, USA, during the Holocene. Geophys. Res. Lett. Version: 1 41 (12) 4300-4307, issn: 0094-8276, ids: AN0SM, doi: 10.1002/2014GL060183
  • Leslie, WR and KB Karnauskas (2014), The Equatorial Undercurrent and TAO Sampling Bias from a Decade at SEA. J. Atmos. Ocean. Technol. Version: 1 31 (9) 2015-2025, issn: 0739-0572, ids: AO4WM, doi: 10.1175/JTECH-D-13-00262.1
  • Sheffield, J, SJ Camargo, R Fu, Q Hu, XA Jiang, N Johnson, KB Karnauskas, ST Kim, J Kinter, S Kumar, B Langenbrunner, E Maloney, A Mariotti, JE Meyerson, JD Neelin, S Nigam, ZT Pan, A Ruiz-Barradas, R Seager, YL Serra, DZ Sun, CZ Wang, SP Xie, JY Yu, T Zhang and M Zhao (2013), North American Climate in CMIP5 Experiments. Part II: Evaluation of Historical Simulations of Intraseasonal to Decadal Variability. J. Clim. Version: 1 26 (23) 9247-9290, issn: 0894-8755, ids: 253AN, doi: 10.1175/JCLI-D-12-00593.1
  • Gierach, MM, M Messie, T Lee, KB Karnauskas and MH Radenac (2013), Biophysical responses near equatorial islands in the Western Pacific Ocean during El Nino/La Nina transitions. Geophys. Res. Lett. Version: 1 40 (20) 5473-5479, issn: 0094-8276, ids: 301DY, doi: 10.1002/2013GL057828
  • Karnauskas, KB (2013), Can we distinguish canonical El Nino from Modoki?. Geophys. Res. Lett. Version: 1 40 (19) 5246-5251, issn: 0094-8276, ids: 243JB, doi: 10.1002/grl.51007
  • Karnauskas, KB, R Seager, A Giannini and AJ Busalacchi (2013), A simple mechanism for the climatological midsummer drought along the Pacific coast of Central America. Atmosfera Version: 1 26 (2) 261-281, issn: 0187-6236, ids: 186ZZ, doi: 10.1016/S0187-6236(13)71075-0
  • Karnauskas, KB, JE Smerdon, R Seager and JF Gonzalez-Rouco (2012), A Pacific Centennial Oscillation Predicted by Coupled GCMs. J. Clim. Version: 1 25 (17) 5943-5961, issn: 0894-8755, ids: 003TF, doi: 10.1175/JCLI-D-11-00421.1
  • Karnauskas, KB and AL Cohen (2012), Equatorial refuge amid tropical warming. Nat. Clim. Chang. Version: 1 2 (7) 530-534, issn: 1758-678X, ids: 972AS, doi: 10.1038/NCLIMATE1499
  • Karnauskas, KB, GC Johnson and R Murtugudde (2012), An Equatorial Ocean Bottleneck in Global Climate Models. J. Clim. Version: 1 25 (1) 343-349, issn: 0894-8755, ids: 876TG, doi: 10.1175/JCLI-D-11-00059.1
  • Cantin, NE, AL Cohen, KB Karnauskas, AM Tarrant and DC McCorkle (2010), Ocean Warming Slows Coral Growth in the Central Red Sea. Science Version: 1 329 (5989) 322-325, issn: 0036-8075, ids: 625VW, doi: 10.1126/science.1190182, PubMed ID: 20647466
  • Karnauskas, KB, R Murtugudde and AJ Busalacchi (2010), Observing the Galapagos-EUC Interaction: Insights and Challenges. J. Phys. Oceanogr. Version: 1 40 (12) 2768-2777, issn: 0022-3670, ids: 708LH, doi: 10.1175/2010JPO4461.1
  • Karnauskas, KB, R Seager, A Kaplan, Y Kushnir and MA Cane (2009), Observed Strengthening of the Zonal Sea Surface Temperature Gradient across the Equatorial Pacific Ocean. J. Clim. Version: 1 22 (16) 4316-4321, issn: 0894-8755, ids: 481IW, doi: 10.1175/2009JCLI2936.1
  • Karnauskas, KB and AJ Busalacchi (2009), The Role of SST in the East Pacific Warm Pool in the Interannual Variability of Central American Rainfall. J. Clim. Version: 1 22 (10) 2605-2623, issn: 0894-8755, ids: 453CG, doi: 10.1175/2008JCLI2468.1
  • Karnauskas, KB and AJ Busalacchi (2009), Mechanisms for the Interannual Variability of SST in the East Pacific Warm Pool. J. Clim. Version: 1 22 (6) 1375-1392, issn: 0894-8755, ids: 431ZT, doi: 10.1175/2008JCLI2467.1
  • Karnauskas, KB, AJ Busalacchi and R Murtugudde (2008), Low-frequency variability and remote forcing of gap winds over the east Pacific warm pool. J. Clim. Version: 1 21 (19) 4901-4918, issn: 0894-8755, ids: 353WO, doi: 10.1175/2008JCLI1771.1
  • Karnauskas, KB, R Murtugudde and AJ Busalacchi (2008), The Effect of the Galapagos Islands on ENSO in Forced Ocean and Hybrid Coupled Models. J. Phys. Oceanogr. Version: 1 38 (11) 2519-2534, issn: 0022-3670, ids: 381TQ, doi: 10.1175/2008JPO3848.1
  • Karnauskas, KB, A Ruiz-Barradas, S Nigam and AJ Busalacchi (2008), North American droughts in ERA-40 global and NCEP North American Regional Reanalyses: A palmer drought severity index perspective. J. Clim. Version: 1 21 (10) 2102-2123, issn: 0894-8755, ids: 306QA, doi: 10.1175/2007JCLI1837.1
  • Karnauskas, KB, R Murtugudde and AJ Busalacchi (2007), The effect of the Galapagos Islands on the equatorial Pacific cold tongue. J. Phys. Oceanogr. Version: 1 37 (5) 1266-1281, issn: 0022-3670, ids: 172LD, doi: 10.1175/JPO3048.1
  • Karnauskas, KB (2006), The African meridional OLR contrast as a diagnostic for Atlantic tropical cyclone activity and implications for predictability. Geophys. Res. Lett. Version: 1 33 (6) , Art. No. L06809, issn: 0094-8276, ids: 026ND, doi: 10.1029/2005GL024865