[AAS03-P12] High-cloud property responses to SST change: sensitivity study using a global nonhydrostatic model
Keywords:cloud property responses, cloud feedback, climate change
In order to investigate the cloud-property response to climate change, we conducted simulations with RCE configurations using a high-resolution nonhydrostatic global circulation model (the Nonhydrostatic Icosahedral Atmospheric Model; NICAM) with the earth-like sphere for simplifying the problem. Sea surface temperatures (SSTs) are fixed at 300K and 304K and a double-moment bulk scheme are used without cumulus parameterization scheme.
We found that high cloud amount increases with SST increase, as consistent with the previous NICAM studies. It was also determined that the change in particularly optically thin clouds whose optical thicknesses were <3 was dominant, and such thin clouds tended to have large particle sizes. These suggests that the slow evaporative property of ice phase clouds and their representability can play one of key roles in the uncertainty of the high-cloud amount change in global warming.