Recent studies carried out to quantify the impacts of continental evaporation on the frequency and intensity of summertime rainfall over North America have shown that higher land surface evaporation may increase summertime rainfall east of the Mississippi and in the region prone to monsoons in southern US and Mexico, reports Science Daily.
"If it starts getting really wet in the east," said Pierre Gentine, Assistant Professor of Applied Mathematics at The Fu Foundation School for Engineering and Applied Science at Columbia University, "then the surface will trigger more rain so it becomes even moister, and this sets up a vicious cycle for floods and droughts. Nature -- i.e. the land surface and the vegetation -- cannot control the rainfall process in the west but it can in the east and in the south. This is really important in our understanding of the persistence of floods and droughts."