Improving oceanic overflow representation in climate models

The Gravity Current Entrainment Climate Process Team (CPT) was established by the U.S. Climate Variability and Predictability (CLIVAR) Program to encourage the translation of new understanding from observations and process models into new parameterizations and hence improve the representation of oceanic overflows in climate models. Global coupled ocean-atmosphere models are increasingly used for climate predictions and projections of future climate change (Solomon et al. 2007). The credibility of these models is limited by their ability to represent climatologically important processes, which occur on scales smaller than the climate model grid scale (currently typically 100 km), such as the overflows shown in Fig. 1. These overflows, or dense gravity currents, result when dense water formed behind confining topographic barriers, or on a continental shelf, escapes into the deep ocean over a sloped sea floor. Important examples of the former are the overflows of dense water from the Nordic seas of the northern North Atlantic (Girton and Sanford 2003; Mauritzen et al. 2005) and •