Identifying parameters to describe local land-atmosphere coupling

The GEWEX Land-Atmosphere System Study/Local Coupling (GLASS/LoCo) project seeks to understand the role of local land atmosphere coupling in the evolution of surface fluxes and state variables including clouds. The theme of land-atmosphere interaction is a research area that is rapidly developing; after the well-known GLACE experiments and various diagnostic studies, new research has evolved in modeling and observing the degree of land-atmosphere coupling on local scales. Questions of interest are: how much is coupling related to local versus "remote" processes, what is the nature and strength of coupling, and how does this change (e.g. for different temporal and spatial scales, geographic regions, and changing climates). As such, this is an important issue on both weather and climate time scales. The GLASS/LoCo working group is investigating diagnostics to quantify land-atmosphere coupling. The "Omega" coupling parameter will be extended to include the role of the evolving atmospheric boundary layer and boundary-layer entrainment. After suitable diagnostics are identified, output from weather and climate models will be used to "map" land-atmosphere coupling in regards to the questions above.