Hsi-Yen Ma

Staff Scientist
Atmospheric, Earth, and Energy Division
Email: ma21@llnl.gov
Phone: +19254225958

Education

  • Ph.D. Atmospheric and Oceanic Sciences, University of California Los Angeles, Los Angeles, CA, 2009
  • M.S. Atmospheric and Oceanic Sciences, University of California Los Angeles, Los Angeles, CA, 2005
  • M.S, Atmospheric Sciences, National Taiwan University, Taipei, Taiwan, 2003
  • B.S, Atmospheric Sciences, National Taiwan University, Taipei, Taiwan, 2001

Research Interests

  • Dynamics of Coupled Atmosphere-Ocean-Land Interactions: Understand the dynamics and physics of interactions and feedback processes among atmosphere, ocean and land surface
  • Climate Modeling: Global and regional climate modeling, sub-grid scale parameterizations of atmospheric convection, clouds, planetary boundary layer, and land surface processes
  • Climate Variability: Understand the global climate variability from diurnal to decadal time scales based on both observations and model experiments
  • Monsoon Climate: Understand the variability and predictability of monsoon flows and precipitation, and their interactions with general circulation from diurnal cycle to decadal time scales, especially for the South American Monsoon System

Synergistic Activities

  • Present: Lead scientist for the LLNL CAPT project: Diagnose and improve the representation of clouds, precipitation and radiation processes in climate models through the application of numerical weather prediction technique
  • Present: Co-lead for the GASS model intercomparison project of diurnal cycle of precipitation
  • 2014-2018: Co-lead for the GASS model intercomparison project of understanding summertime warm bias over the Central United States

Publications

Zhang, T. and coauthors including H.-Y. Ma, 2018: Automatic tuning of the Community Atmospheric Model (CAM5) by using short-term hindcasts with an improved downhill simplex optimization method. Geosci. Model Dev., 11, 5189-5201.

Qian, Y., and coauthors including H.-Y. Ma, 2018: Parametric sensitivity and uncertainty quantification in the version 1 of E3SM Atmosphere Model based on short Perturbed Parameters Ensemble simulations. J. Geophys. Res. Atmos., 123, 13,046-13,073.

Li, J. F., S. Lee, H.-Y. Ma, G. Stephens, and B. Guan, 2018: Assessment of the cloud liquid water from climate models and reanalysis using satellite observations. Terr. Atmos. Ocean. Sci., 29, 653-678, doi: 10.3319/TAO.2018.07.04.01.

Zhang, C., and coauthors including H.-Y. Ma, 2018: CAUSES: Diagnosis of the summertime warm bias in CMIP5 climate models at the ARM Southern Great Plains Sites. J. Geophys. Res. Atmos., 123, 2968–2992.

Van Weverberg, K., and coauthors including H.-Y. Ma, 2018: CAUSES: Attribution of surface radiation biases in NWP and climate models near the U.S. Southern Great Plains. J. Geophys. Res. Atmos., 123, 3612–3644.

Ma, H.-Y., and coauthors, 2018: CAUSES: On the role of surface energy budget errors to the warm surface air temperature error over the Central U.S. J. Geophys. Res. Atmos., 123, 2888–2909.

Morcrette, C. J., and coauthors including H.-Y. Ma, 2018: Introduction to CAUSES: Near-surface temperature errors in NWP and climate model 5-day hindcasts near the Southern Great Plains. J. Geophys. Res. Atmos., 123, 2655–2683.

Qin, Y., Y. Lin, S. Xu, H.-Y. Ma, and S. Xie, 2018: A diagnostic PDF cloud scheme to improve subtropical low clouds in NCAR Community Atmosphere Model (CAM5). J. Adv. Model. Earth Sys., 10, 320–341.

Phillips, T. J., and coauthors including H.-Y. Ma, 2017: Using ARM observations to evaluate climate model simulations of land-atmosphere coupling on the U.S. Southern Great Plains. J. Geophys. Res. Atmos., 122, 11,524–11,548. https://doi.org/10.1002/2017JD027141.  

Zheng, X., and coauthors including H.-Y. Ma, 2017: A cloudy planetary boundary layer oscillation arising from the coupling of turbulence with precipitation in climate simulations. J. Adv. Model. Earth Sys., 9, 1973–1993, doi:10.1002/2017MS000993.

Zheng, X., S. A. Klein, H.-Y. Ma, P. Bogenschutz, A. Gettelman, and V. E. Larson, 2016: Assessment of Marine Boundary Layer Cloud Simulations in the CAM with CLUBB and Updated Microphysics Scheme Based on ARM Observations from the Azores. J. Geophys. Res. Atmos., 121, 8472–8492, doi:10.1002/2016JD025274.

Ma, H.-Y., and coauthors, 2015: An improved hindcast approach for evaluation and diagnosis of physical processes in global climate models. J. Adv. Model. Earth Sys., 7, 1810–1827, doi:10.1002/2015MS000490.

Chandra, A. S., C. Zhang, S. A. Klein, and H.-Y. Ma, 2015: Low clouds over the Tropical Western Pacific in ARM observations and CAM5 simulations. J. Geophys. Res. Atmos., 120, doi:10.1002/2015JD023369.

Ma, P.-L., and coauthors including H.-Y. Ma, 2015: Does Increasing Horizontal Resolution in a Global Climate Model Improve the Simulation of Aerosol-Cloud Interactions? Geophys. Res. Lett., 42, 5058–5065. doi: 10.1002/2015GL064183.

Van Weverberg, K., C. J. Morcrette, H.-Y. Ma, S. A. Klein, and J. C. Petch, 2015: Cloud-regime analysis to find the causes of surface temperature errors in weather and climate models. Q. J. R. Metero. Soc., doi: 10.1002/qj.2603.

Jiang, X., and coauthors including H.-Y. Ma, 2015: Vertical structure and physical processes of the Madden-Julian oscillation: Exploring key model physics in climate simulations. J. Geophys. Res. Atmos., 120, 4718–4748, doi:10.1002/2014JD022375.

Klingaman, N. P. and coauthors including H.-Y. Ma, 2015: Vertical structure and physical processes of the Madden-Julian oscillation: Linking hindcast fidelity to simulated diabatic heating and moistening. J. Geophys. Res. Atmos., 120, 4690–4717,doi:10.1002/2014JD022374.

Boyle, J. S., S. A. Klein, D. D. Lucas, H.-Y. Ma, J. Tannahill, and S. Xie, 2015: The parametric sensitivity of CAM5's MJO. J. Geophys. Res. Atmos., 120, 1424–1444. doi: 10.1002/2014JD022507.

Ma, H.-Y., and coauthors, 2014: On the correspondence between mean forecast errors and climate errors in CMIP5 models. J. Climate. 27, 1781–1798.

Ma, H.-Y., H. Xiao, C. R. Mechoso, Y. Xue, J. D. Neelin, and X. Ji, 2013: On the connection between continental-scale land surface processes and the tropical climate in a coupled ocean-atmosphere-land system. J. Climate. 26, 9006–9025.

Lo, M.-H., C.-M. Wu, H.-Y. Ma, and J. S. Famiglietti, 2013: The response of coastal stratocumulus clouds to agricultural irrigation in California. J. Geophys. Res. Atmos., 118, doi:10.1002/jgrd.50516.

Li, J.-L. F., D. E. Waliser, G. Stephens, S. Lee, T. L’Ecuyer, S. Kato, N. Loeb, and H.-Y. Ma, 2013: Characterizing and understanding radiation budget biases in CMIP3/CMIP5 GCMs, contemporary GCM, and reanalysis. J. Geophys. Res. Atmos., 118, 8166–8184, doi:10.1002/jgrd.50378.

Ma, H.-Y., H. Xiao, C. R. Mechoso, Y. Xue, 2013: Sensitivity of global tropical climate to land surface processes: Mean state and interannual variability. J. Climate, 26, 1818–1837.

Ma, H.-Y., S. Xie, J. S. Boyle, S. A. Klein, and Y. Zhang, 2013: Metrics and diagnostics for precipitation-related processes in climate model short-range hindcasts. J. Climate, 26, 1516–1534.

Xie, S., H.-Y. Ma, J. S. Boyle, S. A. Klein, and Y. Zhang, 2012: On the correspondence between short- and long- timescale systematic errors in CAM4/CAM5 for the Years of Tropical Convection. J. Climate, 25, 7937–7955.

Li, J.-L. F., D. E. Waliser, W.-T. Chen, B. Guan, T. Kubar, G. Stephens, H.-Y. Ma, D. Ming, L. Donner, C. Seman, and L. Horowitz, 2012: An observationally based evaluation of cloud ice water in CMIP3 and CMIP5 GCMs and contemporary reanalyses using contemporary satellite data. J. Geophys. Res., 117, D16105, doi:10.1029/2012JD017640.

Xiao H., C.-M. Wu, C. R. Mechoso, and H.-Y. Ma, 2012: A treatment for the stratocumulus-to-cumulus transition in GCMs. Clim. Dyn. doi: 10.1007/s00382-012-1342-z.

Ma, H.-Y., M. Köhler, J.-L. Li, J. D. Farrara, C. R. Mechoso, R. Forbes, and D. E. Waliser, 2012: Evaluation of an ice cloud parameterization based on a dynamical-microphysical lifetime concept using CloudSat observations and the ERA-Interim reanalysis. J. Geophys. Res., 117, D05210, doi:10.1029/2011JD016275.

Ma, H.-Y., X. Ji, J. D. Neelin, and C. R. Mechoso 2011: Mechanisms for precipitation variability of the eastern Brazil/SACZ convective margin. J. Climate, 24, 3445–3456.

Ma, H.-Y., C. R. Mechoso, Y. Xue, H. Xiao, C.-M. Wu, J.-L. Li, and F. De Sales, 2010: Impact of land surface processes on the South American warm season climate. Clim. Dyn. doi: 10.1007/s00382-010-0813-3.

Losada, T., B. Rodriguez-Fonseca, C. R. Mechoso, and H.-Y. Ma, 2007: Impacts of SST anomalies on the North Atlantic atmospheric circulation: a case study for the northern winter 1995/1996. Clim. Dyn., 29, 807-819.

Ma, H.-Y., and C. R. Mechoso, 2007: Submonthly Variability in the South American Monsoon System. J. Meteor. Soc. Japan, 85A, 395-401.