Rainfall Microphysical Properties of Landfalling Typhoon Yagi (201814) Based on the Observations of Micro Rain Radar and Cloud Radar in Shandong, China

Abstract

The development and evolution of precipitation microphysical parameters and the vertical structure characteristics associated with Typhoon Yagi (201814) are analyzed in the city of Jinan, Shandong Province based primarily on the observations of a micro rain radar (MRR), a cloud radar, and a disdrometer. The precipitation process is further subdivided into four types: convective, stratiform, mixed, and light precipitation according to the ground disdrometer data, which is in agreement with the vertical profile of the radar reflectivity detected by the MRR. Vertical winds may be the main source of MRR retrieval error during convective precipitation. Convective precipitation has the shortest duration but makes the largest contribution to the cumulative precipitation. Collision-coalescence is the main microphysical process of stratiform precipitation and light precipitation below the bright band observed by the MRR. It is worth noting that as Typhoon Yagi (201814) transformed into an extratropical cyclone, its raindrop size distributions no longer had the characteristics of maritime precipitation, but become more typical of the characteristic of continental precipitation, which represents a very different raindrop size distribution from that which is normally observed in a landfalling typhoon.