Abstract:

This presentation will provide an overview of the next generation development of atmospheric physics for the DOE Energy Exascale Earth System Model (E3SM) Version 3 (E3SMv3). The current atmospheric physics in E3SMv1 and v2 have been largely updated during the development. Specifically, the UC Irvine’s interactive chemistry mechanisms have been implemented in E3SM along with the improved representation of Nitrate, Second Organic Aerosol (SOA), and stratosphere sulfate aerosols. The Predicted Particle Properties (P3) scheme is now used to handle cloud microphysical processes and improve the treatment of ice. A more sophisticated cloud microphysics scheme is incorporated into the Zhang-McFarlane (ZM) deep convection scheme for representing cloud microphysics for convective clouds. A further modification is made to the ZM scheme so that its cloud mass flux is sensitive to large-scale circulation. In addition, mesoscale convective heating is added on top of the deep convective heating from ZM.

The new atmospheric physics package largely enhances the E3SM capability for coupling across different Earth systems. It also reduces several long-standing model errors in simulating model diurnal and intra-seasonal variability while retaining the good representation of the mean-state climate as shown in E3SMv2. The signal of the Madden Julian Oscillation, Kelvin waves, and inertial gravity waves is much stronger than E3SMv2. The phase and amplitude of the diurnal cycle of precipitation across many land and oceanic regions are also improved. Initial results from an experimental configuration of coupled E3SMv3 show a largely improved simulation of historical surface temperature trend, which has been a major outstanding issue for E3SMv1 and v2. More details will be given at the seminar.