青海高原短时强降水天气的葵花-8卫星监测预警特征对比分析  

Comparative Analysis of Himawari-8 Satellite Monitoring and Early Warning Characteristics in Short-Time Heavy Precipitation Weather over Qinghai Plateau

作　　者：朱平[1] 肖建设[2] ZHU Ping;XIAO Jianshe(College of Electronic Engineering,Chengdu University of Information Technology,Chengdu 610225,Sichuan,China;Qinghai Province Meteorological Observatory,Xining 810001,Qinghai,China)

机构地区：[1]青海省气象台,青海西宁810001 [2]青海省气象科学研究所,青海西宁810001

出　　处：《高原气象》2022年第2期502-514,共13页Plateau Meteorology

基　　金：国家自然科学基金项目(41865006);青海省科技厅应用基础研究项目(2021-ZJ-726);2021年中国气象局创新发展专项(CXFZ2021Z034)。

摘　　要：为获得青海高原(以下简称高原)对流云团的强降水监测预警特征和预警方法,使用葵花-8卫星数据跟踪识别高原典型强降水天气过程的对流云团,计算并分析具有提前预警意义的云团特征参数。结果表明:(1)本文提出的对流云团识别的改进多通道法,经与传统多通道法对比检验,证明所得云团更接近对流主体,该方法适用于高原对流云团识别。(2)对流形成到成熟阶段,特征参数起伏变化,但红外与水汽通道亮温差(DTB13)和云顶亮温(Tmin)整体下降,云顶亮温梯度(GTmax)整体上升;在对流发展阶段仅红外1和2通道亮温差(DTB12)平均可达预警极值,在成熟阶段则是Tmin、DTB13、GTmax、深对流指数(DCI)等平均可达预警极值。高原上强降水天气的对流云多发展成深对流,降水发生在云团特征参数极值附近,短时强降水发生在深对流云区内特定云顶(上冲云顶或近似上冲云顶)所在特征参数极值区内或边缘附近。(3)特征参数极值对一般降水和强降水的开始时间分别提前0~1 h和0.5~4.5 h出现,在西风型流场下对强降水开始的提前时间相对较长。降水开始前,副高型流场下对流云团向深对流发展变化最剧烈,表现为DCI和GTmax平均最大,且DTB12均值最小,而西风型流场下积云发展相对弱。降水开始后,西风型流场下的深对流相对浅但云顶变化仍剧烈,表现为DCI和Tmin均值分别更低,但GTmax和DTB13平均更大,而在低涡切变型流场下的对流发展相对较深厚。(4)提出高原短时强降水天气的对流云团预警方法为:当对流云团发展到具有特定云顶,其所在尺度为50 km范围云区的Tmin≤223 K、DCI≥20 K、GTmax≥18 K、DTB12≤0 K、DTB13≤3 K等同时满足时,可预警在该范围内将产生或继续产生短时强降水,经检验该预警方法在高原深对流云短时强降水预警中的实用性较高。In order to obtain the heavy precipitation monitoring and early warning characteristics and early warning methods of convective clouds over Qinghai Plateau(hereinafter referred to as plateau),the Himawari-8 satellite datum in typical heavy precipitation weather processes over the plateau were used to track and identify convective clouds,the clouds characteristic parameters with early warning significance were calculated and analyzed. The results show that:(1)An improved multi-channel method for convective clouds identification was proposed in this paper,Compared with the traditional multi-channel method,it was proved that the obtained clouds were closer to the convective main body,and was suitable for convective clouds identification over the plateau.(2)From convection formation to maturity,the characteristic parameters fluctuated,but the minimum brightness temperature difference between infrared channel 1 and water vapor channel(DTB13)and the minimum brightness temperature(Tmin)of cloud top decreased as a whole,and the maximum brightness temperature gradient(GTmax)of cloud top increased as a whole. In the convective development stage,only the minimum brightness temperature difference between infrared channels 1 and 2(DTB12)reached the early warning extreme value on average. And in the mature stage,it reached the early warning extreme value on average,such as Tmin,DTB13,GTmax and deep convection index(DCI). Convective clouds in heavy precipitation weather over the plateau mostly developed into deep convection,and precipitation occured near the extreme value of characteristic parameters of clouds,and the short-time heavy precipitation occured in the extreme value area or near the edge of the characteristic parameters of the specific cloud tops(upwelling cloud tops or approximate upwelling cloud tops)in the deep convective cloud area.(3)The extreme values of characteristic parameters appeared 0~1 h and 0. 5~4. 5 h ahead of the start time of general precipitation and heavy precipitation respectively,and its advance

关 键 词：青海高原 葵花-8卫星 云团识别 监测预警参数 短时强降水 大气流场 

分 类 号：P412.27[天文地球—大气科学及气象学]