Can precipitation help us attribute the temperature “hiatus”?

Abstract:

The ability of the atmosphere to balance the latent heat of precipitation (P) with radiative cooling provides a strong energetic constraint on global-mean precipitation. The P response to forcing may be partitioned into a “slow” temperature-mediated component, and a “fast” response that depends on the nature of the external forcing. Abrupt GHG forcing, for example, leads to an immediate suppression of global-mean P followed by a slower temperature-mediated increase. Previous studies have established that this slow response is roughly independent of forcing, and thus removing the temperature-mediated component from the observed precipitation response yields a picture of the forcing-dependent fast response. The GPCP satellite dataset indicates that, in recent years, global-mean precipitation has decreased even as global-mean surface temperature has remained roughly constant. Does this atypical behavior reveal the signatures of external forcing agents? Using observational data and CMIP5 single-forcing experiments, we examine the roles of various external forcing agents in the hiatus decade and explore their effect on the scaling of precipitation with temperature.