Regional Variability of Precipitation in Tropical Cyclones Over the Western North Pacific Revealed by the GPM Dual-Frequency Precipitation Radar and Microwave Imager
Regional Variability of Precipitation in Tropical Cyclones Over the Western North Pacific Revealed by the GPM Dual-Frequency Precipitation Radar and Microwave Imager
复制标题
GPM双频降水雷达和微波成像仪揭示西北太平洋热带气旋降水区域变化
DOI：
10.1029/2019jd031075
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发表时间：
2019-11-16
影响因子：
4.4
通讯作者：
Yang, Yuanjian
中科院分区：
文献类型：
--
作者：
Chen, Fengjiao;Fu, Yunfei;Yang, Yuanjian
了解热带气旋的降水微物理对于利用数值天气模式预报热带气旋的路径和强度至关重要。利用全球降水测量卫星上的双频降水雷达和微波成像仪对北太平洋西部地区近5年的TCs观测资料，研究了TCs不同区域的降水特征、微物理过程及其与冰散射信号的关系。在靠近TC中心的区域，风暴顶高（STH）和近地面降雨率高，水成物浓度高，质量加权平均直径（Dm）相对较小。在外TC区，反射率因子（Ze）和Dm的分布随着平均Dm的增大而变宽。熔化层以下的Ze和Dm值普遍增大，表明碰撞-合并作用起主导作用。当STH小于5 km， 89 GHz极化校正温度大于250 K时，碰撞聚结发生的概率大于90%。当STH超过5 km时，眼壁区域也以碰撞合并过程为主；而在雨带区域，破碎过程的影响增大。
A knowledge of precipitation microphysics of tropical cyclones (TCs) is crucial for forecasts of the TC track and intensity using numerical weather models. Based on five years of measurements of TCs over the western North Pacific from the dual-frequency precipitation radar and the microwave imager on board the Global Precipitation Measurement satellite, the precipitation characteristics and microphysical processes in different regions of TCs and their associations with ice scattering signals are investigated. In the region close to the TC center, the storm top height (STH) and near-surface rain rate are high, and the hydrometeors have a high concentration and a relatively low mass-weighted mean diameter (Dm). In the outer TC region, the distributions of the reflectivity factor (Ze) and Dm become broader as the mean Dm increases. Ze and Dm values generally increase below the melting layer, indicating the predominant role of collision-coalescence processes. The occurrence probability of collision-coalescence is greater than 90% when STH is less than 5 km and the polarization-corrected temperature at 89 GHz is greater than 250 K. When the STH exceeds 5 km, the collision-coalescence process is also predominant in the eyewall region; however, the influence of the breakup process increases in the rainband regions.