摘要
利用2014—2015年的云和地球辐射能量系统CERES Aqua Edition 4A SSF的云产品以及地面小时降水数据,对辽宁地区(38.5°N—43.5°N、118.5°E—126°E)云宏微观特征参量的时空分布进行分析,并研究各参数与降水的相关性,建立基于云光学厚度(COD)与云水路径(CWP)的降水云识别指标。结果表明,夏季云层发展旺盛,云量(CF)、COD、云顶高度(CTH)以及CWP值均较高,平均值分别为62.7%、17.9、6.5 km和252.1 g·m-2,而冬季云参数的值最低,分别为48.3%、7.0、3.4 km和106.2 g·m-2,仅云粒子有效半径(ER)显著高于其他季节。受地形影响,西部地区(122°E以西)的成云条件较东部差,除CTH较高外,其他云参量均较东部偏低。除云顶气压(CTP)和云顶温度(CTT)外,CF、COD、CWP和ER均随降水强度的增加而增加,说明云层越深厚降水强度越大,云含水量越高,粒子尺度越大。筛选出的与降水强度相关性最高的COD与CWP作为降水云识别因子,利用TS评分及HSS评分方法,选取评分值最高时对应的COD和CWP作为降水云的识别阈值,分别为35和415 g·m-2。
Based on the cloud product of CERES(clouds and earth’s radiant energy system)Aqua Edition 4A SSF(single scanner footprint)data and hourly precipitation observation data,the spatial and temporal distribution characteristics of micro-and macro-scopic cloud parameters in Liaoning Province(38.5°N-43.5°N,118.5°E-126°E)were analyzed.In addition,the correlation between cloud parameters and rainfall intensities was studied and the precipitation identification indexes based on COD(cloud optical depth)and CWP(cloud water path)were established.The results show that cloud developed more vigorous in summer,and the average of CF(cloud fraction),COD,CTH(cloud top height)and CWP reached as high as 62.7%,17.9,6.5 km and 252.1 g·m-2,respectively,but in winter they were 48.3%,7.0,3.4 km and 106.2 g·m-2,respectively.Only ER(the effective radius)of cloud particles reached the maximum in winter.Due to the influence of terrain,the generation condition of cloud in the east(east of 122°E)of Liaoning was better than that in the west(west of 122°E).Except the CTH was higher in the western part of Liaoning Province,all the other cloud parameters were lower than that in the eastern part.The CF,COD,CWP and ER of particles all increased with rainfall intensities,while CTP(cloud top pressure)and CTT(cloud top temperature)showed opposite trend,indicating that the stronger the precipitation was,the thicker cloud layer was,the higher water content was and the larger particle size was.COD and CWP were selected as the precipitating cloud identification factors for its higher correlation coefficients with precipitation intensities.Based on the score of TS(threat score)and HSS(Heidke skill score),35 and 415 g·m-2 for COD and CWP was selected,corresponding to the maximum TS and HSS scores.
作者
孙丽
张晋广
杨磊
赵姝慧
SUN Li;ZHANG Jinguang;YANG Lei;ZHAO Shuhui(Liaoning Weather Modification Office,Shenyang 110166,China;Institute of Atmospheric Environment,CMA,Shenyang 110166,China;Liaoning Meteorological Disaster Monitoring and Early Warning Center,Shenyang 110166,China)
出处
《干旱气象》
2020年第4期612-618,共7页
Journal of Arid Meteorology
基金
国家自然科学基金青年基金(41705127)
辽宁省自然科学基金计划重点项目(20180540086、2019 JH2/10200019)
辽宁省气象局科研项目(LNGJ201905、201611)共同资助。
关键词
云参数
降水云识别
CERES
cloud parameters
precipitating cloud identification
CERES
