Multi-scale Interaction Processes Associated with Development of a Sub-Synoptic-Scale Depression on the Meiyu-Baiu Frontal Zone

Abstract

A sub-synoptic-scale depression, with a wavelengtJh of 2000-3000 km, propagated along the Meiyu-Baiu frontal zone from China to Northwestern Pacific during 03-05 July 1991. We investigated the development and change in the structure of the frontal depression in detail, by using the Geostationary Meteorological Satellite (GMS) Infrared (IR) and objective global analysis (GANAL) data, of the Japan Meteorological Agency.
This sub-synoptic-scale depression develops in association with low/middle-level vorticity maxima and meso-x-scale cloud systems. However, the simple one-to-one correspondence among them is not lasting for the whole life time of the depression, but the multiple coupling among the depression, vorticity cores and cloud systems occurs during the evolution process. The vertical structure of the depression varies in accordance with the low-level and middle-level vorticity cores, indicating the differentmovement and evolution in the coupling process.
The present study thus demonstrates an example of multi-scale interactions related to the complicated evolution process of the sub-synoptic-scale depression on the Baiu frontal zone.