基于地基微波辐射计反演的济南地区水汽r及云液态水特征

摘要

基于德国RPG公司研制的14通道地基微波辐射计(RPG-HATRPO-G3)反演的2014年10月至2015年9月济南地区的水汽和液态水产品,分析了济南地区水汽和云液态水不同季节的月变化、日变化特征及其在强对流天气与小雨天气中的变化趋势.结果表明:2014年10月至2015年9月济南地区柱大气积分水汽量(Integrated Water Vapour,IWV)具有明显的月变化特征,其变化趋势与多年(1981—2010年)月平均降水量相关性较好,IWV夏季最高、冬季最低,四季IWV均具有弱的日变化特征,四季IWV标准偏差按照夏季、秋季、春季、冬季的顺序递减.对于济南地区春季、夏季、秋季3个季节有云无雨和降水前后液态水路径(Liquid Water Path,LWP)的数据,春季LWP可用数据量最少,夏季LWP可用数据量最多;月LWP在0—200 g·m-2范围内的数据占总数据的比例最多,LWP数值越大,其所占比例越小.月LWP大于1000 g·m-2数据的比例随着夏季的临近和降水量的逐渐增加也呈增加的趋势.IWV和LWP在强对流过程发生前均明显增长,数值大于1000 g·m-2的LWP数据比例为53.41%;而小雨天气发生前IWV呈波动上升的趋势,LWP仅在临近降水时才明显增大,LWP数值主要分布在0—200 g·m-2之间,占总数据的比例为86.56%.%Using integrated Water Vapor ( IWV) and Liquid Water Path ( LWP) data determined from 14-channel ground-based microwave radiometer named RPG-HATPRO-G3 during October of 2014 and September of 2015 in Ji′nan,seasonal,monthly,diurnal variation characteristics of IWV and LWP,as well as their variation tendencies in severe convective and spit weather were analyzed. The results show that IWV exhibited apparent monthly variation during the research period. The tendency of these variations had a relatively good correlation with the long-term monthly mean precipitations during 1981 and 2010,with the highest value in summer and the lowest value in win-ter. Diurnal variations of IWV were weak in all seasons,and the seasonal standard deviations were in the decreasing order of summer,autumn,spring,and winter. After counting the number of LWP data in spring,summer and au-tumn seasons,the number of available LWP data in cloudy days is the minimum in spring and the maximum in summer. The number of frequency the monthly LWP peaks between 0-200 g·m-2 and declines with the increase of LWP. The number of frequency of the monthly LWP more than 1000 g·m-2 gradually increases with the increasing precipitation in summer season. IWV and LWP increase significantly ahead of an intensive convective weather,and LWP above 1000 g·m-2 accounts for 53. 41%. IWV increases in a wave pattern before a period of spit weather, while LWP increases significantly near the beginning of spit weather. Monthly LWP concentrated between 0-200 g·m-2 with the frequency of 86. 56%.