I am an atmospheric scientist within the Atmospheric, Earth, and Energy Division at LLNL. My research interests mainly focus on clouds, precipitation, convection, and their representations in global climate models. More broadly, my interests include climate modeling, dynamics of coupled atmosphere-ocean-land interactions, climate variability, monsoon climate, and application of AI techniques to improve Earth system predictions.

Synergistic Activities

• PI for LLNL Laboratory Directed Research & Development Project to improve precipitation and extreme predictions in DOE E3SM using artificial intelligence techniques
• Co-Investigator for DOE RGMA project to improve MJO representation in DOE SCREAM
• Co-Investigator for LLNL THREAD SFA Project to improve cloud processes in DOE SCREAM using DOE ARM data
• Lead Scientist for the US Dept. of Energy Cloud-Associated Parameterizations Testbed (CAPT) project
• Co-lead for the international GASS modeling intercomparison project of understanding summertime warm bias over the Central U.S. (CAUSES: Clouds Above United States and Errors at the Surface)
• Co-lead for the international GASS modeling intercomparison project of improving the simulation of diurnal and sub-diurnal precipitation over different climate regimes

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

Google Scholar Link

Selected Publications:

Tao, C., and coauthors including H.-Y. Ma, 2023: Diurnal cycle of precipitation over tropical and midlatitude lands: GCM Inter-Comparison. Q. J. R. Metero. Soc., https://doi.org/10.1002/qj.4629.

Galea, D., and coauthors including H.-Y. Ma, 2023: Deep learning image segmentation for atmospheric rivers. Artificial Intelligence for the Earth Systems, doi: 10.1175/AIES-D-23-0048.1.

Qin, H., and coauthors including H.-Y. Ma, 2023: Summertime near-surface temperature biases over the Central United States in convection-permitting simulations. J. Geophys. Res. Atmos., 128, e2023JD038624.

Tao, C., and coauthors including H.-Y. Ma, 2022: Diurnal cycle of precipitation over global monsoon systems in CMIP6 simulations. Climate Dynamics, doi:10.1007/s00382-022-06546-0.

Su, C.-Y., W.-T. Chen, C.-M. Wu, H.-Y. Ma, 2022: Object-Based Evaluation of Tropical Precipitation Systems in DYAMOND Simulations over the Maritime Continent. J. Meteor. Soc. Japan, 100,  https://doi.org/10.2151/jmsj.2022-033.

Ma, H.-Y., and coauthors, 2022: Superior daily and sub-daily precipitation statistics for intense and long-lived storms in global storm- resolving models. Geophysical Research Letters, 49, e2021GL096759.

Caldwell, P. M., and coauthors including H.-Y. Ma, 2021: Convection-permitting simulations with the E3SM global atmosphere model. J. Adv. Model. Earth Sys., doi: 10.1029/2021MS002544.

Pan, B., and coauthors including H.-Y. Ma, 2021: Learning to correct climate projection biases. J. Adv. Model. Earth Sys., 13, e2021MS002509. doi: 10.1029/2021MS002509.

Ma, H.-Y., and coauthors, 2021: Evaluation of the causes of wet-season dry biases over Amazonia in CAM5. J. Geophys. Res. Atmos., 123, 2888–2909.

Ma, H.-Y., and coauthors, 2021: On the correspondence between seasonal forecast and long-term climate errors in sea surface temperatures. J. Climate, 34, 427–446.

Ma, H.-Y., and coauthors, 2021: A multi-year short-range hindcast experiment with CESM1 for evaluating climate model moist processes from diurnal to interannual timescales. Geosci. Model Dev., 14, 73–90.

Siongco, A. C., H.-Y. Ma, S. A. Klein, S. Xie, A. R. Karspeck, K. Raeder, J. L. Anderson, 2020: A hindcast approach to diagnosing the equatorial Pacific cold tongue SST bias in CESM1. J. Climate, 33, 1437–1453.

Xie, S., and coauthors including H.-Y. Ma, 2019: Improved diurnal cycle of precipitation in E3SM with a revised convective triggering function. J. Adv. Model. Earth Sys., 11, 2290–2310. 

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.

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.

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.

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.

2023     LLNL Physical and Life Sciences Directorate Award in Institutional Impact

2023     LLNL Physical and Life Sciences Directorate Award in Publication

2019     LLNL Deputy Director for Science and Technology Excellence in Publication Award

2018     LLNL Physical and Life Sciences Directorate Award in Publication

2018     LLNL Spot Award