Modeling the Effect of Land Surface Evaporation Variability on Precipitation Variability. Part II: Time- and Space-Scale structure

Abstract This is the second of a two-part article investigating the impact of variations of land surface evaporability on the interannual variability of precipitation. The first goal of this part is to analyze the relationship between the atmospheric internal variability and the evaporative forcings. The hypothesis that the sum of ocean- and atmosphere-induced variabilities can be linearly amplified by the land variability is critically revisited and generally found not applicable to the climate model used and the numerical experiments conducted. A set of parameters to evaluate the departure from the linear behavior is defined, quantifying the impact of the different forcings over the total variability. Some areas of the world (e.g., the monsoon region, the continental United States, and southeastern Africa), where the impact of internal atmospheric dynamics on precipitation variability is small compared to the impact of the evaporative forcings, are localized. Over these areas, the variability of precipi...