基于Himawari-8卫星资料的青藏高原对流系统识别

Convective System Identification of the Tibetan Plateau Based on Himawari-8 Satellite Data

本文利用Himawari-8卫星的高级成像仪(HW8)的中心波长为10.4 μm的全盘观测标准数据,基于结合了传统区域重叠(AOL)跟踪法和卡尔曼滤波(KF)法的一个跟踪对流系统的新算法,对青藏高原区域(25~45?N, 80~105?E) 2016年7月1日至15日的对流系统进行识别跟踪。这半个月内,利用新算法一共跟踪到了青藏高原区域的13个不同强度的对流系统,根据对流系统的不同特征将其分为三类:1) 通常意义上的对流系统,包含了从生成到发展再到消亡一个完整的生命周期;2) 从一个较大系统上分裂出的对流;3) 生成发展到一定程度后并入其他系统的对流。文中分别选择一个典型个例进行分析。分析结果显示,三个对流系统有着不同的特征(时空、亮温、尺寸、移动轨迹等),它们对降水的影响也有所不同。前两个对流系统强度较小,对降水的影响也不大;后者则是青藏高原较少有的强对流系统,对降水影响较大。

Advanced Himawari imager (HW8) overall observation standard data with a center wavelength of 10.4 μm from Himawari-8 satellite were used in this paper to identify and track convection in the Tibetan Plateau region (25 - 45?N, 80 - 105?E) from July 1 to 15, 2016. We used a novel algorithm that combines the advantages of both traditional area overlap (AOL) tracking and Kalman filtering (KF) to detect the convective system. In this half-month, a total of 13 different intensity convective systems in the Tibetan Plateau were tracked by the algorithm. Convective systems are classified into three categories by different characteristics: 1) The convective system in the usual sense, including from generation to development to extinction, a complete life cycle;2) Convection split from a larger system;3) Convection that merges into other systems after development to a certain extent. Three certain classic cases were chosen to analyze. Analyses show that three convective systems have different characteristics (such as time and space, brightness temperature, size, movement, etc.), and their effects on precipitation are also different. The first two convective systems have less intensity and have little effect on precipitation;the latter is a strong convective system, which has a bigger impact on precipitation.