A Numerical Case Study of East Asian Coastal Cyclogenesis

Abstract

Abstract The relative importance of latent beat release and surface sensible heat flux in a case of East Asian coastal cyclogenesis were investigated by performing numerical experiments with the ECMWF limited-area model. In the control experiment that included all physical processes, the cyclone developed rapidly in a way similar to that observed. In the experiment without latent beat feedback, only a shallow low appeared when the upper short-wave trough approached the inverted surface trough situated on the coast, but no further development took place. This suggests that the baroclinic forcing was enhanced by the feedback of physical process. An increasingly unbalanced subtropical jet streak, an ageostrophic low-level jet and the associated vertical indirect circulation prior to the major development were well simulated in the Control but they were not simulated in the “dry” experiment (without latent heating). The latent heating had a profound impact on the amplifying jet streak circulation and the vert...