The transition between stratocumulus clouds, which deck the cold upwelling waters of the easter ocean basins, to more broken, cumulus under stratocumulus, over warmer waters in the trades has been investigated by scientists at the MPI-M to help better understand meteorological controls on cloudiness. Such controls are fundamental to parameterizations (statistical descriptions) of clouds, which underlie much of the current uncertainty in predictions of global warming.

These simulations were performed on 256 CPUs of blizzard, with a grid spacing of tens of meters, and a time step of less than a second. Altogether one simulation consumes more than 100,000 CPU hours, and thus requires state of the art computational resources. The research was carried out by Irina Sandu and Bjorn Stevens, with support from the Alexander von Humboldt Foundation and the Max-Planck Society (Sandu, I. and B. Stevens, 2011: On the factors modulating the stratocumulus to cumulus transitions. In: Journal of the Atmospheric Sciences 68, 1865-1881. doi: 10.1175/2011JAS3614.1); visualizations were rendered by Michael Böttinger of DKRZ.