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Stephen A. Klein

Portrait of  Stephen A. Klein

  • Title
    Staff Scientist
  • Email
  • Phone
    (925) 423-9777
  • Organization
    Not Available


For over 30 years, Stephen Klein has been an atmospheric research scientist. Since 2004, he has been at the Department of Energy’s Lawrence Livermore National Laboratory, where he is a member of the Cloud Processes Research and Modeling Group under the Atmospheric, Earth and Energy Division of the Physical Life Sciences Directorate. Prior to 2004, he was a research scientist at two leading climate and weather modeling laboratories: the National Oceanic and Atmospheric Administration’s Geophysical Fluid Dynamics Laboratory and the European Centre for Medium Range Weather Forecasts.

Research Interests

  • Clouds
  • The role of clouds in climate change
  • The representation of clouds in numerical models of the atmosphere

Ph.D., Atmospheric Sciences, University of Washington, 1994

B.A., Physics, Oberlin College, 1989

My Scopus Profile 

Selected Publications:

  1. Klein, Stephen A., A. Hall, J. R. Norris, and R. Pincus, 2017: Low-cloud feedbacks from cloud-controlling factors: A review. Surv. Geophys.38, 1307–1329, doi: 10.1007/s10712-017-9433-3.
  2. Klein, Stephen A., and A. Hall, 2015: Emergent constraints for cloud feedbacks. Current Climate Change Reports, 1, 276–287, doi: 10.1007/s40641-015-0027-1.
  3. Klein, Stephen A., Y. Zhang, M. D. Zelinka, R. N. Pincus, J. Boyle, and P. J. Gleckler, 2013: Are climate model simulations of clouds improving? An evaluation using the ISCCP simulator. J. Geophys. Res.118, 1329–1342, doi: 10.1002/jgrd.50141.
  4. Klein, Stephen A., et al., 2009: Intercomparison of model simulations of mixed-phase clouds observed during the ARM Mixed-Phase Arctic Cloud Experiment. Part I: Single layer cloud. Quart. J. Roy. Met. Soc.135, 979–1002, doi: 10.1002/qj.416.
  5. The GFDL Global Atmospheric Modeling Development Team, 2004: The new GFDL global atmosphere and land model AM2/LM2: Evaluation with prescribed SST simulations. J. Climate17, 4641–4673, doi: 10.1175/JCLI-3223.1. (S. A. Klein was the corresponding author of this article.)
  6. Klein, Stephen A. and C. Jakob, 1999: Validation and sensitivities of frontal clouds simulated by the ECMWF model. Mon. Wea. Rev.127, 2514–2531, doi: 10.1175/1520-0493(1999)127<2514:VASOFC>2.0.CO;2.
  7. Klein, Stephen A. and D. L. Hartmann, 1993: The seasonal cycle of low stratiform clouds. J. Climate6, 1587–1606, doi: 10.1175/1520-0442(1993)006<1587:TSCOLS>2.0.CO;2.
  8. Zelinka, M. D., T. A. Myers, D. T. McCoy, S. Po-Chedley, P. M. Caldwell, P. Ceppi, S. A. Klein, and K. E. Taylor, 2020: Causes of higher climate sensitivity in CMIP6 models. Geophys. Res. Lett., 47, e2019GL085782, doi: 10.1029/2019GL085782.
  9. Zhou, C., M. D. Zelinka, and S. A. Klein, 2016: Impact of decadal cloud variations on the Earth’s energy budget. Nat. Geosci., 9, 871–874, doi: 10.1038/ngeo2828.
  10. Ma, H.-Y., S. Xie, S. A. Klein, K. D. Williams, J. S. Boyle, S. Bony, H. Douville, S. Fermepin, B. Medeiros, S. Tyteca, M. Watanabe, and D. Williamson, 2014: On the correspondence between mean forecast errors and climate errors in CMIP5 models. J. Climate27, 1781–1798, doi: 10.1175/JCLI-D-13-00474.1.
  11. Zelinka, M. D., S. A. Klein, and D. L. Hartmann, 2012a: Computing and partitioning cloud feedbacks using cloud property histograms. Part I: Cloud radiative kernels. J. Climate25, 3715–3735, doi: 10.1175/JCLI-D-11-00248.1.
  12. Zhang Y. and S. A. Klein, 2010: Mechanisms affecting the transition from shallow to deep convection over land: Inferences from observations of the diurnal cycle collected at the ARM Southern Great Plains site. J. Atmos. Sci.67, 2943–2959, doi: 10.1175/2010JAS3366.1.
  • 2020, Fellow of the American Meteorological Society
  • 2013, LLNL’s Physical and Life Sciences Directorate Award as an Outstanding Postdoc Mentor in recognition of exemplary mentoring, coaching, leadership, as well as scientific contributions to the community of climate and atmospheric researchers at LLNL.
  • 2012, American Geophysical Union “Ascent” Award for mid-career scientists in the fields of the atmospheric and climate sciences who have demonstrated excellence in research and leadership in their field.
  • 2009, U.S. Department of Energy’s Appreciation Award in recognition of contributions as the leader of the Cloud Modeling Working Group of the Atmospheric Radiation Measurement Program.