Collaborative Research: Climate Process Team on Low-Latitude Cloud Feedbacks on Climate Sensitivity

National Aeronautics & Space Administration Langley Research Ctr, Hampton VA

Investigators

Abstract

This grant will support a collaborative research project among eight research groups and three modeling centers working as a Climate Process and Modeling Team (CPT). It's a focused effort aimed at better representing processes affecting low-latitude cloud feedbacks in climate models, by involving experts on the details of cloud, turbulence and convection processes more directly into parameterization development. The first research goal is to fully understand the very different response of subtropical boundary layer cloud in the National Center for Atmospheric Research (NCAR) Community Atmospheric Model (CAM) and the Geophysical Fluid Dynamics Laboratory's (GFDL) atmospheric general circulation model (GCM) to CO2 doubling. The second more ambitious goal is to analyze cloud feedbacks from tropical convective cloud regimes, which intimately couple parameterizations of microphysical, convective, radiative and turbulent processes. These goals will be achieved by a closely coordinated scientist core group working with three modeling centers. They will use diagnostic studies based on a suite of regional and global observations, single-column analysis and modeling efforts, GCM sensitivity studies and parameterization-swap tests using the NCAR CAM, GFDL's atmospheric GCM, the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center's GCMs, and 'superparameterization' simulations. The anticipated broader impacts of the CPT are to (1) reduce uncertainty in climate model projections of future climate change, a basic US need for rational formulation of national and international adaptation and regulatory strategies and energy policy. It should also (2) improve the physical basis of leading US climate models as well as fostering collaborations that sustain future improvements in these models, benefiting the entire spectrum of US climate science research.