Cloud-scale simulation study of Typhoon Hagupit (2008) Part II: Impact of cloud microphysical latent heat processes on typhoon intensity

Abstract

Based on a control experiment (CTL), we conduct three sensitivity experiments to focus on the influence of different cloud microphysical latent heat processes on the intensity of Typhoon Hagupit (2008). The results show the following: (1) Because of changes in the latent heat budget, different cloud microphysical processes have little influence on the typhoon track, but have significant influence on its intensity, propagation speed, cloud and precipitation, and thermal and dynamic structures. (2) The positive feedback effect between latent heat release and convection modulates typhoon intensity. In the absence of latent heat release of deposition and sublimation, it is difficult to produce deep convection, the cloud wall is weak and disorganized, the warm core structure is shallow, low-level radial inflow and high-level radial outflow weaken, the cyclonic circulation weakens, and the intensity decreases. In the absence of the latent heat release of evaporation and cooling of rain water, low levels are warm and humid, the development of convection in the cloud wall is strong, there is a deep warm core structure, low-level radial inflow and radial outflow at high level are strengthened, and the cyclonic circulation and intensity are strengthened. (3) The dominant latent heat processes that strengthen the typhoon are water vapor condensation into cloud water, and the deposition growth of snow and of cloud ice. The main latent heat processes weakening the typhoon are evaporation of rainwater, sublimation of snow, and melting of graupel.