加密自动站在极端短时强降水发生前的精细化特征分析  

Analysis of Detailed Characteristics of Encrypted Automatic Station before Occurrence of Extreme Short-time Heavy Rainfall

作　　者：靳振华 赵金霞 卜清军 JIN Zhenhua;ZHAO Jinxia;BU Qingjun(Tianjin Binhai New Area Meteorological Office,Tianjin 300457,China)

机构地区：[1]天津市滨海新区气象局,天津300457

出　　处：《天津科技》2020年第4期87-92,96,共7页Tianjin Science & Technology

基　　金：天津市气象局一般项目“天津沿岸极端短时强降水的分布特征及成因分析”(201702ybxm01)。

摘　　要：利用地面加密自动气象站资料及常规气象观测资料,分析2006-2016年4~10月小时雨强大于50 mm/h的极端短时强降水个例的各气象要素场在短时强降水发生之前2 h的变化规律,结果表明:①产生极端短时强降水的天气类型包括冷涡型、西风槽型和西北气流型,冷涡型强降水气象要素变化最为剧烈,其他2种类型稍弱。②1 h变温、3 h变压、风场在3类个例中均有比较明显的变化规律,气温变化幅度稍弱,露点温度和相对湿度是表现最弱的2个要素,相对湿度表现更弱,是指示性不强的物理量。③在强降水发生2 h前气象要素场的变化规律一般表现为等值线密集带在上游生成并快速向下游移动,常伴有大值中心的出现。风场主要表现为风向风速的辐合或切变,天气越剧烈风场变化越明显;偏东、偏南气流的建立对于水汽输送的作用需引起注意。在风场变化不明显的少数强降水过程中,在天气发生前一般也都有偏东、偏南气流的长时间维持。Based on the encrypted automatic surface station and conventional observation data,the change rule of each meteorological element field in 2 hours before the occurrence of short-time heavy rainfall is analyzed in the case of extreme short-time heavy rainfall with rain intensity greater than 50 mm/h from April to October over 2006 to 2016.The results show:(1)The extreme short-time heavy rainfall weather types include:cold vortex,westerly trough and northwest airflow type,the change of cold vortex heavy rainfall meteorological factors is the most dramatic,the other two types are slightly weak.(2)The change rules of 1 hour temperature change,3 hour pressure change and wind field are more obvious,the temperature changes slightly,dew point temperature and relative humidity are the two weakest elements,relative humidity is weaker,which is a not indicative physical quantity.(3)The variation rule of the meteorological elements field generally shows that the dense line of the contour is generated in the upstream and moved downstream rapidly 2 hours before the occurrence of heavy rainfall,often accompanied by the appearance of large value centers.The wind field is mainly manifested as convergence or shear of wind direction and wind speed.The weather is more intense if the change of wind field is more obvious.Attention should be paid to the effect of the establishment of the eastward and southward airflow on the water vapor transport.In the few strong precipitation processes that have no obvious change in the wind field,the eastward and southward airflow is generally maintained for a long time before the heavy rainfall.

关 键 词：极端短时强降水 加密自动站 气象要素变化 

分 类 号：N945[自然科学总论—系统科学]