Research with Fine - Resolution Global Atmospheric Models

The dawn of the modern era of global climate modeling may be traced to the work of Syukuro Manabe, Joseph Smagorinsky, and their colleagues who in 1965 described the first integration of a multi-level comprehensive atmospheric general circulation model (AGCM) that included treatments of the radiation, the dynamics and the hydrological cycle (Manabe et al., 1965). This model had the equivalent of about T30 resolution1 in the horizontal and had 9 vertical numerical levels representing the atmosphere from the ground to the model top near 30 km. It is somewhat remarkable that in the intervening decades— despite the enormous growth of computational power—for most climate research applications investigators have largely been satisfied with only about 2–3 times the horizontal and vertical resolution used in that original model. Researchers have typically devoted their ever-increasing computer power principally to making longer integrations and incorporating more sophisticated parameterizations into their AGCMs. As a recent example, almost all the models involved in the Intergovernmental Panel on Climate Change (IPCC) intercomparison described in their 2007 Fourth Assessment Report have horizontal resolution corresponding to ~T63 or less, and have less than 30 levels in the vertical. Although mainstream efforts in climate modeling have been devoted to rather coarse resolution models, for the last Research with Fine-Resolution Global Atmospheric Models A Personal Perspective