Collaborative Research: Validated Radiation and Convection Model Impacts on Climate Simulations

Atmospheric And Environmental Research Inc, Lexington MA

Investigators

Abstract

The impact of a data-validated radiation model RRTM, on multi-year climate simulations will be examined under this research effort. Previous work has shown that the improved accuracy provided by the RRTM in the longwave modifies the temperature structure, water vapor distribution, and tropical circulation in the CCM3 simulations. However comparisons between the RRTM and CCM3 in the shortwave show substantial clear sky differences that complicate the interpretation of the RRTM longwave impact on CCM3 in some regions. Experiments proposed here will consider the effect of both longwave and shortwave improvements. In addition, by comparing RRTM-modeled and observed spectral radiances, there are substantial discrepancies in the ability of the CCM3 to simulate upper tropospheric water vapor that appear unrelated to radiation. The collaboration with MIT (PI Emanuel) will examine the role of convection in this process.