Land-atmosphere interactions at the subgrid scale in a climate model

Abstract:

This study aims to investigate land-atmosphere interactions using subgrid-scale data produced by the National Center for Atmospheric Research’s (NCAR’s) earth system model. Specifically, we are interested in lake evaporation changes in a warming climate, deforestation effects on surface climate, and enhanced temperatures in urban land. Common to these processes is that they occur at local scales that are too small to be resolved by climate models. In NCAR’s earth system model, each grid consists of up to five land units (vegetated, lake, urban, glacier, crop). These land units share the same atmospheric forcing at the first grid height but have their own land surface parameterizations and surface energy balance calculations. So far, attention has focused on grid-mean quantities but subgrid outputs have not been fully utilized. In this paper, we will discuss strategies for evaluating validity of the subgrid surface variables and develop analytical frameworks for interpreting the results in relation to land use changes and radiative forcing.