The Simple Cloud-Resolving E3SM Atmosphere Model (SCREAM)

Numerical models are a critical tool for predicting Earth’s future climate conditions due to the complex and inter-related processes controlling weather. While simulating the whole planet imposes severe computational challenges, global coverage is nonetheless necessary as local behavior propagates rapidly to distant areas of the globe. To solve these challenges, Peter Caldwell (AEED) and collaborators are using the Energy Exascale Earth System Model (E3SM) to create a new global atmosphere model—the Simple Cloud-Resolving E3SM Atmosphere Model (SCREAM). The E3SM project was born from the Department of Energy’s need for quantitative information to use in decisions about climate future.

The SCREAM article, “Convection-Permitting Simulations With the E3SM Global Atmosphere Model,” was published in the Journal of Advances in Modeling Earth Systems and made the cover of the November 2021 issue. The paper highlights how Caldwell and researchers implemented a new global 3.25 kilometer version of the E3SM atmosphere model and its behavior in a 40-day northern-hemisphere wintertime simulation. This high-resolution model is 30 times finer than the typical resolution for global climate models (GCMs). As a result of this improved resolution, precipitation is greatly improved both in the timing of its diurnal cycle and the distribution of light versus heavy rainfall. The new model also captures the structure of important weather events, such as tropical and extratropical cyclones, atmospheric rivers, and cold air outbreaks which are poorly captured by typical GCMs.

[P.M. Caldwell, C.R. Terai, B.R. Hillman, N.D. Keen, P.A. Bogenshutz, W. Lin, H. Beydoun, M.A. Taylor, L. Bertagna, A. Bradley, T.C. Clevenger, A.S. Donahue, C. Eldred, J.G. Foucar, J.C. Golaz, O. Guba, R.L. Jacob, J. Johnson, J. Krishna, W. Liu, K.G. Pressel, A.G. Salinger, B. Singh, A. Steyer, P. Ullrich, D. Wu, X. Yuan, J. Shpund, H.Y. Ma, C.S Zender, Convection-Permitting Simulations with the E3SM Global Atmosphere Model, Journal of Advances in Modeling Earth Systems (2021), doi: 10.1029/2021MS002544.]