Representation of Carbon and Water Cycles in Global and Convection-Permitting Models

Abstract:

The coupling of carbon and water cycles has important impacts on the climate system while current GCMs have a poor representation of related small-scale processes, such as convection, precipitation, surface fluxes, and photosynthesis, thus leading to significant biases in the representation of climatology, especially over the lands. Multi-scale climate models show advantages as they can accurately simulate both small-scale physical and physiological processes and large-scale motions. We use the comprehensive Community Earth System Model (CESM) and its multi-scale convection-permitting version (referred as the "super-parameterization" model, SP)—to understand how resolved convection and clouds modulate the diurnal and seasonal cycles of water, carbon, and energy at the land surface, and ultimately influence the future climatology. Moreover, we specifically investigate the impact of clouds on plant photosynthesis over continental regions from both the radiative and hydrological views. We run the high-emission future scenario (BSSP585) experiments from 2016 to 2100 with these two models. In order to avoid the TOA radiation imbalance in SP, we use the SST from the CESM experiment to drive the SP experiment. Detailed setup and results will be presented in the meeting.