On dynamic and thermodynamic components of cloud changes

摘要: Clouds are sensitive to changes in both the large-scale circulation and thermodynamic structure of atmosphere. In tropics, temperature that occur on seasonal decadal time scales often associated with changes. Therefore, it is difficult determine part cloud variations results from a change dynamics may result itself. This study proposes simple framework unravel dynamic non-dynamic (referred as thermodynamic) components response climate variations. It used analyze contrasted response, prescribed ocean warming, tropically-averaged radiative forcing (CRF) simulated by ECMWF, LMD UKMO models. each model, component largely dominates CRF at regional scale, but this explains most average imposed perturbation. shown strongly depends behaviour low-level clouds regions moderate subsidence (e.g. trade wind regions). These exhibit sensitivity changes, mostly their huge statistical weight large influence tropical radiation budget. Several propositions made for assessing motions using satellite observations meteorological analyses one hand, mesoscale models other hand.