Most coupled climate models predict decreases in the Atlantic Meridional Overturning Circulation given continued anthropogenic greenhouse gas increases, but they disagree on the extent of the decrease. Here I examine the behavior of several models to see how much of the variation can be explained by such factors as differences in high latitude sea surface density, Southern Ocean wind stress, and details of model formulation.
Coupled climate models have trouble reproducing the sea surface tempeature (SST), clouds, and other aspects of the eastern South Pacific Ocean. Too-warm model SST may lead to other problems in the mean and variability, undermining our confidence in the models and degrading climate predictions. In this NOAA-funded project, Schopf (GMU and COLA), Harrison (GFDL) and I have been looking at the ocean's contribution to the model bias. More generally, we are trying to understand how wind-driven upwelling helps determine coastal cooling and how it fits in with the large-scale circulation. We are working on a couple of manuscripts based on the following recent presentations.
Southern Ocean wind stress is thought to help determine the time-mean global meridional overturning circulation, a key feature of the ocean which is important for climate. This NSF-funded project, With GMU grad student Carlos Cruz, looks at how changes in the wind forcing can drive decadal changes in the global circulation.
Drake Passage Effect Without the Drake Passage -- A nontechnical description of one reseach project.
Last modified: 4 Nov, 2010.