Walter Michael Hannah

(he/him)

Portrait of Walter Michael Hannah
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  • Title
    Climate Scientist and Model Developer
  • Email
    hannah6@llnl.gov
  • Phone
    (925) 424-2241
  • Organization
    PLS-AEED-ATMOSPHERIC, EARTH, ENERGY

I am an atmospheric scientist with a background researching Tropical convection and atmospheric dynamics. I am primarily interested in the interaction between convection and large-scale circulations because of the many poorly understood processes in this area. Atmospheric models are a useful tool for understanding these issues on a deeper level, which is why I have spent most of my career working with them in various capacities.

Most of my effort at LLNL is spent on the multi-scale modelling framework configuration (also known as super-parameterization) of the Department of Energy’s Earth system model, E3SM. By taking advantage of exascale computers, this project will allow much more detailed study of regional impacts of anthropogenic climate change. I also contribute to the development of the standard E3SM, as well as the Simple Cloud Resolving E3SM Atmosphere Model (SCREAM).

Ph.D. Atmospheric Science, Colorado State University, Fort Collins, CO

  1. Yu, S., Hannah, W. M., Peng, L., … & Pritchard, M. S. (2023). ClimSim: An open large-scale dataset for training high-resolution physics emulators in hybrid multi-scale climate simulators. arXiv preprint arXiv:2306.08754.
  2. Hannah, W. M., K. G. Pressel, 2022: Transporting CRM Variance in a Multiscale Modelling Framework, Geosci. Model Dev., 15, 8999–9013.
  3. Hannah, W. M., A. M. Bradley, O. Guba, Q. Tang, J.-C. Golaz, and J. Wolfe, 2021: Separating Physics and Dynamics grids for Improved Computational Efficiency in Spectral Element Earth System Models. J. Adv. Model. Earth Sys., 13, e2020MS002419.
  4. Hannah, W. M., C. R. Jones, B. R. Hillman, M. R. Norman, M. A. Taylor, D. A. Bader, L. R. Leung, M. S. Pritchard, M. D. Branson, G. Lin, K. G. Pressel, and J. M. Lee, 2020: Initial Results from the Super-Parameterized E3SM. J. Adv. Model. Earth Sys., 12, e2019MS001863.
  5. Hannah, W. M., 2017: Entrainment vs. Dilution in Tropical Deep Convection. J. Atmos. Sci., 74, 3725–3747.
  6. Hannah, W. M., and A. Aiyyer, 2017: Reduced African Easterly Wave Activity with Quadrupled CO2 in the Super-Parameterized CESM. J. Climate, 30, 8253–8274.
  7. Russell, J. O., A. Aiyyer, J. D. White, and W. M. Hannah, 2017: Revisiting the Connection Between African Easterly Waves and Atlantic Tropical Cyclogenesis. Geophys. Res. Lett., 43.
  8. Hannah, W. M., B. E. Mapes, and G. S. Elsaesser, 2016: A Lagrangian View of Moisture Dynamics During DYNAMO. J. Atmos. Sci., 73, 1967-1985.