A Model of Typhoons with Outflow and Subsidence Layers

摘要

The Nimbus and ESSA pictures of hurricanes and typhoons reveal that longitudinal bands of convective clouds appear outside a relatively clear annular zone around the storm and these longitudinal bands at times are accompanied by well-defined transverse bands which are characterized by mesoscale cloud streaks. In order to generalize the model of typhoons accompanied by inner and outer rainbands, a modified model of typhoons was proposed. In this model, a subsidence layer was added to the original outflow layer in order to permit the air to descend from the outflow to the subsidence layer. The model also permits the air in the subsidence layer to ascend to the outflow layer by entraining the air into the updraft. The middle layer of the previous model was also used to transport the absolute angular momentum inside the radar echoes through the subsidence layer to the outflow layer. (Author)