The Chase research group focuses on modeling and observational studies of the effects of the land surface and changing landcover (for example, deforestation, desertification, and irrigation) and their effects on regional and global climate. Tropical and sub-tropical Monsoon systems have been a particular area of study. We also have projects in the general area of non-linear geophysics such as examining climate feedbacks in the hydrological cycle and the effects of a variable sun on climate model simulations.