Abstract
An aircraft observation was conducted over the East China Sea to reveal detailed distributions of wind and moisture around the Baiu frontal zone. Using a numerical simulation, the structure of the Baiu frontal zone was examined and four airstreams around the zone were identified: northeasterly, west-southwesterly, and southwesterly along the Baiu frontal cloud zone, as well as southwesterly along the oceanic zone. Each airstream had different characteristics of stratification. These differences and the convergence of the airstreams resulted in two different rainfall areas: a weak and wide rainfall area in the northern part of the cloud zone, and an intense and narrow rainfall area in the southern part.
