2016～2017年凌汛期黄河内蒙河段快速封河的天气成因分析  

Analysis of Weather Cause of Quick Freeze-up in Inner Mongolia Reach of Yellow River during Ice-Flood Period from 2016 to 2017

作　　者：张荣刚[1] 靳莉君[1] 张利娜[1] 张保龙[2] ZHANG Ronggang;JIN Lijun;ZHANG Lina;ZHANG Baolong(Bureau of Hydrology,YRCC,Zhengzhou 450004,China;Meteorological Bureau of Bayannaoer City,Bayannaoer 015000,China)

机构地区：[1]黄河水利委员会水文局,河南郑州450004 [2]巴彦淖尔市气象局,内蒙古巴彦淖尔015000

出　　处：《水文》2018年第2期93-96,共4页Journal of China Hydrology

基　　金：水利部公益性行业科研专项(201301062)

摘　　要：利用常规观测资料,对2016年11月20~23日内蒙河段强降温天气过程进行诊断分析。结果表明:造成这次快速封河的强降温天气过程,与贝湖附近的横槽转竖密切相关。500h Pa上由里海到西西伯利亚平原上空有高压脊强烈发展,脊崩溃是横槽转竖及强冷空气向南爆发的预报着眼点。随着高空横槽转竖并南下,从地面冷高压主体分裂出来的小高压不断东移南下影响内蒙河段。低层冷槽在移动过程中不断加强,并在偏北风急流作用下产生强冷平流,加剧了内蒙河段的温度梯度,共同造成了本次内蒙河段强冷空气天气过程。当北西伯利亚低地出现大量冷空气堆积,且有典型天气形势配合冷空气活动时,要考虑内蒙地区将有强降温过程;如遇内蒙河段河道流量较小,在沿河各站48h降幅达到寒潮标准,最大降幅在14℃以上时,要考虑内蒙河段从流凌到封河的历时将会较短。Based on the observation data of MICAPS,this paper analyzed the strong temperature drop in the Inner Mongolia Reach during 20-23 November,2016.The results show that the strong temperature drop leading to the rapid freeze-up of the river is closely related to the vertical trough in the vicinity of the Beihu Lake.There is a high pressure ridge development over 500hPa fromthe Caspian Sea to theWest Siberian Plain,ofwhich the ridgecollapse isthe forecastkey ofthe verticalandstrong coldairto the south.With the high-altitude transverse trough to the vertical south,the small high-pressure split out of the ground cold high-pressure constantly moving southward and influence the Inner Mongolia River.The cold troughs in the lower reaches of Inner Mongolia have been intensified during the course of the movement,and the strong cold advection occurred under the northerly winds,which aggravated the temperature gradients in the Inner Mongolia Reach and resulted in the strong cold air weather.When a large number of cold air accumulated in the northern lowlands of Siberia,and a typical weather situation activated,forecasters should consider that the Inner Mongolia will have strong cooling process.At the same time,if the river flow is small,with each station along the riverdropped by acold wave standard in 48h,and thebiggestdrop isbeyond 14℃,forecastersshould considerthatthe InnerMongolia willquickly change fromtheice flowto freeze up.

关 键 词：内蒙河段 环流形势 冷高压 横槽转竖 冷平流 

分 类 号：P426.616[天文地球—大气科学及气象学]