OP-E1.1 Next Generation Development (NGD) of Atmospheric Physics for E3SM v2/v3
| Poster Title | An Overview of Next Generation Development (NGD) of Atmospheric Physics for E3SM v2/v3 |
|---|---|
| Authors | Shaocheng Xie |
| First Author | Shaocheng Xie |
| Session Type | E3SM |
| Session ID | E1 |
| Submission Type | Presentation |
| Group | NGD - Atmospheric Physics |
| Experiment | |
| Poster Link |
Abstract
An Overview of Next Generation Development (NGD) of Atmospheric Physics for E3SM v2/v3
Shaocheng Xie
Lawrence Livermore National Laboratory, Livermore, California, USA
Abstract
The DOE Energy Exascale and Earth System Model (E3SM) Atmosphere Model (EAM) has undergone significant changes in physics and model resolution during its development from its version 0 (EAMv0) to version 1 (EAMv1). In particular, it implemented a simplified third-order turbulence closure parameterization (CLUBB; Cloud Layers Unified By Binormals) to unify the treatment of planetary boundary layer turbulence, shallow convection, and cloud macrophysics and remove the unrealistic separation among these physical processes. The model resolution was increased from 10 to 0.250 in horizontal and from 30 layers to 72 layers in vertical. These changes have resulted in an overall considerable improvement in EAMv1 simulated mean state of clouds, cloud radiative forcing, and precipitation in comparison with EAMv0. However, EAMv1 continues to have difficulty in producing the right amount of low clouds in the subtropical stratocumulus regions with much fewer stratocumulus compared to observations. The simulated precipitation still shows large regional biases over both lands and oceans and problems in capturing the diurnal and intra-seasonal variability. In addition, the current E3SM atmospheric physical parameterizations, in particular the deep convection scheme, are not well scale-aware. Significant model tuning is needed as resolution increases.
The goal of the E3SM next generation development (NGD) – atmospheric physics project is to address these outstanding model issues and enhance the model’s capability to address uncertainty in predicting future changes in Earth system. This includes 1) improving the representation of various physical processes related to convection, particularly developing a unified scale-aware scheme for shallow and deep convection that allows a smooth transition across the scales and between these two types of convections; 2) improving the treatment of frozen particles in cloud microphysics with the more accurate and flexible cloud microphysical scheme, the Predicted Particle Properties (P3); 3) improving the treatment of aerosol and dust physics; and 4) improving radiative treatment of clouds and aerosols. In addition, we will implement the UCI fast chemistry into E3SM to improve the interaction with aerosols and coupling to BGC. More details about the NGD-Atmospheric Physics project will be discussed at the meeting.