Yunyan Zhang

(she/her)

Portrait of  Yunyan Zhang
  • Title
    Group Leader of Climate Analysis
  • Email
    zhang25@llnl.gov
  • Phone
    (925) 422-5778
  • Organization
    PLS-AEED-ATMOSPHERIC, EARTH, ENERGY

RESEARCH INTERESTS

It has always been fascinating for me to study the life cycle of clouds. My research interests include diurnal cycle, low-level stratiform clouds, shallow cumulus, shallow to deep convection transition, cloud climate feedback, and the interactive processes between land surface, atmospheric boundary layer and clouds.

I made observational analysis for mechanistic understanding of clouds and convection using satellite data and both in-situ and remote sensing data from field campaigns and long-term observations at DOE ARM climate facilities. I performed numerical modeling and analysis using fine-scale modeling tools such as large eddy simulations and single column models. I diagnosed model performance for validation and improvement, including traditional low-resolution global climate models with parameterized cloud and convection processes, Multi-scale Modeling Framework (MMF) with super-parameterization, and high-resolution kilometer grid scale global storm resolving models (GSRMs). I also used to develop forcing data sets to drive cloud resolving model or single-column model through constrained variational analysis to support DOE ASR cloud modeling activities for various field campaigns.
 

Ph.D., Atmospheric and Oceanic Sciences, University of California at Los Angeles

B.S., Atmospheric Sciences, Peking University, Beijing, China

SELECTED PUBLICATIONS

Su, T. and Y. Zhang, 2024: Deep-learning-driven simulations of boundary layer clouds over the Southern Great Plains, Geosci. Model Dev., 17, 6319–6336, https://doi.org/10.5194/gmd-17-6319-2024

Su, T. and Y. Zhang, 2024: Deep-learning-derived planetary boundary layer height from conventional meteorological measurements, Atmos. Chem. Phys., 24, 6477–6493, https://doi.org/10.5194/acp-24-6477-2024

Tian, J., Y. Zhang, S.A. Klein, C. R. Terai, P. M. Caldwell, H. Beydoun, P. Bogenschutz, H.-Y. Ma, A. S. Donahue, 2024: How well does the DOE global storm resolving model simulate clouds and precipitation over the Amazon? Geophysical Research Letters, 51, e2023GL108113. https://doi.org/10.1029/2023GL108113

Zheng, X., Y. Zhang, S. A. Klein, M. Zhang, Z. Zhang, M. Deng, J. Tian, C. R. Terai, B. Geerts, P. Caldwell, P. A. Bogenschutz, 2024: Using satellite and ARM observations to evaluate cold air outbreak cloud transitions in E3SM global storm-resolving simulations. Geophysical Research Letters, 51, e2024GL109175. https://doi.org/10.1029/2024GL109175

Tian, J., Y. Zhang, S. A. Klein, R. Ӧktem, & L. Wang, 2022: How does land cover and its heterogeneity length scales affect the formation of summertime shallow cumulus clouds in observations from the US Southern Great Plains? Geophys. Res. Lett.49, e2021GL097070. https://doi.org/10.1029/2021GL097070

Tian, Y., Y. Zhang, S. A. Klein, 2022: What determines the number and the timing of pulses in afternoon precipitation in Green Ocean Amazon (GoAmazon) observations? Geophys. Res. Lett. 49, e2021GL096075, https://doi.org/10.1029/2021GL096075

Tao, C., Y. Zhang, Q. Tang, H.-Y. Ma, V. P. Ghate, S. Tang, S. Xie, and J. A. Santanello, 2021: Land–Atmosphere Coupling at the U.S. Southern Great Plains: A Comparison on Local Convective Regimes between ARM Observations, Reanalysis, and Climate Model Simulations. J. Hydrometeor., 22, 463-481. https://doi.org/10.1175/JHM-D-20-0078.1

Tian, Y., Y. Zhang, S. A. Klein, C. Schumacher, 2021: Interpreting the diurnal cycle of clouds and precipitation in the ARM GoAmazon observations: Shallow to deep convection transition. J. Geophys. Res. Atmos., 126, e2020JD033766. https://doi.org/10.1029/2020JD033766

Tian, J., Y. Zhang, S. A. Klein, L. Wang, R. Ӧktem and D. M. Romps, 2021: Summertime continental shallow cumulus cloud detection using GOES-16 satellite and ground-based stereo cameras at the DOE ARM Southern Great Plains site. Remote Sens., 13, 2309. https://doi.org/10.3390/rs13122309

Tao, C., Y. Zhang, S. Tang, Q. Tang, H.-Y. Ma, S. Xie, and M. Zhang, 2019: Regional moisture budget and land‐atmosphere coupling over the U.S. Southern Great Plains inferred from the ARM long‐term observations. J. Geophys. Res. Atmos., 124. https://doi.org/10.1029/2019JD030585

Lee, J., Y. Zhang, and S. A. Klein, 2019: The effect of land surface heterogeneity and background wind on shallow cumulus clouds and the transition to deeper convection. J. Atmos. Sci., 76, 401-419. https://journals.ametsoc.org/doi/abs/10.1175/JAS-D-18-0196.1

Terai, C. R., Y. Zhang, S. A. Klein, M. D. Zelinka, J. C. Chiu, and Q. Min, 2019: Mechanisms behind the extratropical stratiform low‐cloud optical depth response to temperature in ARM site observations, J. Geophys. Res. Atmos., 124, 2127– 2147. https://doi.org/10.1029/2018JD029359

Lareau, N. P., Y. Zhang, and S. A. Klein, 2018: Observed boundary layer controls on shallow cumulus at the ARM Southern Great Plains Site. J. Atmos. Sci., 75, 2235–2255, https://doi.org/10.1175/JAS-D-17-0244.1

Zhang, Y., S.A. Klein, J. Fan, A.S. Chandra, P. Kollias, S. Xie, and S. Tang, 2017: Large-Eddy Simulation of Shallow Cumulus over Land: A Composite Case Based on ARM Long-Term Observations at Its Southern Great Plains Site. J. Atmos. Sci., 74, 3229–3251, https://doi.org/10.1175/JAS-D-16-0317.1

Xie, S., Y. Zhang, S. Giangrande, M. Jensen, R. McCoy, and M. Zhang, 2014:  Interactions between Cumulus Convection and Its Environment as Revealed by the MC3E Sounding Array. J. Geophys. Res. Atmos., https://doi.org/10.1002/2014JD022011

Zhang, Y. and S.A. Klein, 2013: Factors Controlling the Vertical Extent of Fair-Weather Shallow Cumulus Clouds over Land: Investigation of Diurnal-Cycle Observations Collected at the ARM Southern Great Plains Site. J. Atmos. Sci., 70, 1297–1315, https://doi.org/10.1175/JAS-D-12-0131.1

Caldwell, P., Y. Zhang and S. A. Klein, 2013: CMIP3 low cloud feedback interpreted through a mixed-layer model.  J. Climate 26, 1607-1625. https://doi.org/10.1175/JCLI-D-12-00188.1

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, https://doi.org/10.1175/2010JAS3366.1

Zhang, Y., B. Stevens, B. Medeiros, and M. Ghil, 2009: Low-Cloud Fraction, Lower-Tropospheric Stability, and Large-Scale Divergence. J. Climate, 22, 4827–4844, https://doi.org/10.1175/2009JCLI2891.1

Zhang, Y., S. A. Klein, C. Liu, B. Tian, R. T. Marchand, J. M. Haynes, R. B. McCoy, Y. Zhang, and T. P. Ackerman, 2008: On the diurnal cycle of deep convection, high-level cloud, and upper troposphere water vapor in the Multiscale Modeling Framework, J. Geophys. Res. Atmos., 113, D16105, https://doi.org/10.1029/2008JD009905

Zhang, Y., B. Stevens and M. Ghil, 2005: On the diurnal cycle and susceptibility to aerosol concentration in a stratocumulus-topped mixed layer. Quart. J. Roy. Meteor. Soc., 131, 1567–1583. https://doi.org/10.1256/qj.04.103

  • US Department of Energy, Early Career Research Program Award, 2015. $2,500K funding in total for 5 years. Winning proposal titled "The Effect of Soil Moisture and Surface Heterogeneity on Clouds and Precipitation: Inferences from ARM observations and Large Eddy Simulations".

 

  • Director's Science and Technology Early and Mid-Career Award, LLNL, 2023
  • Directorate External Leadership and Recognition Award, PLS, LLNL, 2024. "Outstanding scientific leadership in national and international research communities that study clouds, convection, and land-atmosphere interaction."
  • Directorate Publication Award, PLS, LLNL, 2024. "Overview paper describing version 2 of the DOE’s 
    Regionally Refined Energy Exascale Earth System Model (E3SM)."
  • Directorate Postdoctoral Advisor Award, PLS, LLNL, 2023. "For helping her five mentees build a strong foundation for long-term success in the sciences"  
  • Directorate Institutional Impact Award, PLS, LLNL, 2023. "For developing THREAD (Tying in High Resolution E3SM and ARM Data), a new Scientific Focus Area integrating global storm–resolving models and long-term ground-based observations" 
  • Spot Award, Atmospheric, Earth and Energy Division, PLS, LLNL, 2016, 2017, 2018

 

  • Chancellor Dissertation Fellowship, University of California, Los Angeles, 2005
  • Best Student Poster Award, American Meteorological Society the 16th Symposium on Boundary Layers and Turbulence, Portland, Maine, 2004
  • IGPP Fellowship, University of California, Los Angeles, 1999-2001
  • Chancellor Fellowship, University of California, Los Angeles, 1999

SYNERGISTIC ACTIVITIES 

  • Lead Principal Investigator (PI). DOE Atmospheric System Research (ASR) Program, Science Focus Area project, "Tying in High Resolution E3SM with ARM Data (THREAD)", newly funded since October 2022  
  • Principal Investigator. US Department of Energy, Early Career Research Program Award project, "The Effect of Soil Moisture and Surface Heterogeneity on Clouds and Precipitation: Inferences from ARM observations and Large Eddy Simulations", 2015-2020.    

 

  • DOE ASR Program, Co-Chair Warm Boundary Layer Processes Working Group, 2017 to 2023 
  • DOE Atmospheric Radiation Measurement (ARM) Program, Science Board member 2020-2022
  • DOE ARM User Executive Committee member since 2021
  • DOE ARM-ASR Coordination Team (AACT) member, since 2017

 

  • Associate editor, Journal of Geophysical Research - Atmospheres since 2022
  • Member of the GEWEX Global Land/Atmosphere System Study (GLASS) Panel and GEWEX Data and Analysis Panel (GDAP) since 2021; member of the GLASS Local Land-Atmosphere Coupling (LoCo) working group since 2016
  • Organizing committee member, “The future of the atmospheric large eddy simulation”, the DOE ASR LES workshop, 2022; “Improving understanding of land atmosphere interactions through integration of surface flux and atmospheric boundary layer measurements”, the AmeriFlux Land-Atmosphere Interaction workshop in collaboration with the DOE ASR and ARM programs, 2021; “Improvement and Calibration of Clouds in Models”, Toulouse, France, 2021; “Understanding and Modeling Atmospheric Processes (UMAP)”, 2nd PAN-GASS meeting, Australia, 2018

 

  • LLNL Laboratory Directed Research and Development (LDRD), Energy, Earth, and Atmospheric S&T committee, 2017 to 2019
  • Mentor to 7 postdocs in recent years