天山北麓两次暴雪天气对比分析  

Comparative analysis of two blizzard weather mechanisms in the northern piedmonts of Tianshan Mountains

作　　者：牟欢 赵丽[2] 孙硕阳 汤浩 贾健[4] MOU Huan;ZHAO Li;SUN Shuo-yang;TANG Hao;JIA Jian(Xinjiang Meteorological Observatory,Urumqi 830002,Xinjiang,China;Xinjiang School of Information Engineering,Urumqi 830013,Xinjiang,China;Binjiang College,Nanjing University of Information Science&Technology,Nanjing 210044,Jiangsu,China;Urumqi Meteorological Bureau,Urumqi 830002,Xinjiang,China)

机构地区：[1]新疆维吾尔自治区气象台,新疆乌鲁木齐830002 [2]新疆信息工程学校,新疆乌鲁木齐830013 [3]南京信息工程大学滨江学院,江苏南京210044 [4]乌鲁木齐市气象局,新疆乌鲁木齐830002

出　　处：《干旱区地理》2019年第6期1262-1272,共11页Arid Land Geography

基　　金：中国气象局预报员专项(CMAYBY2017-083)资助

摘　　要：利用常规气象观测资料、NCEP/NCAR 1°×1°(美国气象环境预报中心-NCEP和美国国家大气研究中心-NCAR)再分析资料、全球同化系统(GDAS)数据、引入基于拉格朗日方法的气流轨迹模式(HYSPLIT_v4.9)、FY-2E卫星资料、多普勒雷达产品,对2014年2月和2016年3月天山北麓的两次暴雪天气过程进行了诊断分析。结果表明:两次暴雪过程的降雪落区均是出现在500 hPa槽前、低层切变或辐合区、高层辐散区、温度平流梯度在垂直方向大值区、相当黑体亮度温度(TBB)中心边缘的梯度较大处重叠区域。通过诊断发现,2016年暴雪天气的暴雪区上空有类似于暴雨过程的湿对称不稳定存在,使得大气潜在不稳定能量较大,为暴雪提供了不稳定机制。而在2014年暴雪天气中没有发现湿对称不稳定,说明条件对称不稳定并不是造成暴雪的唯一原因,还可能受别的不稳定机制或动力因子、热力因子影响,但其对单位时间内降雪强度有明显的增幅作用。分析雷达回波特征的演变发现,雷达回波中心的强度、持续时间、范围与强降雪中心的变化一致。Two heavy blizzards in northern Xinjiang,China happened on February 23,2014 and March 2,2016.Although the central location and snowfall size of the two blizzards were similar,the hourly snowfall and snowfall duration of the two snowstorms were different.In particular,during the heavy snowfall in March 2016,the maximum hourly snowfall at some observation stations were nearly 4.0 mm,reaching the historical maximum since the setup of the recording system.But the maximum hourly snowfall of the blizzard in February 2014 was only 1.8 mm at the observatory.In order to understand the difference between the two blizzard weather events,this paper investigated the weather process about the two events using the meteorological observational data,NCEP/NCAR 1°×1°re-analysis data,the GDAS(Global Data Assimilation System)data and the HYSPLIT4.9 model,FY-2 E data and Doppler radar product.The results are summarized as following:The snowfall areas of the two blizzards were both located in the overlaying area in front of the 500 hPa trough with shearing or converging at the low-levels,diverging at the high-level,and large temperature advection gradient in the vertical direction,and in the larger gradient of the edge of the cloud TBB center.Domestic researchers has studied more about the effects of frontal forcing and symmetric instability on heavy rain,but their application in blizzard was less involved.Diagnosing atmospheric stability through moist potential vorticity revealed that the location of the blizzard center in 2016 and the area with moist potential vorticity negative value were basically the same.There was a moist symmetric instability over the blizzard area which is similar to that of a rainstorm.This mechanism can help the inclined updraft be formed and developed,then cause the release of a large potential unstable energy in the atmosphere and provide unstable mechanism for blizzard.When moist symmetric instability was gone,the hourly snowfall was also decreased.Therefore,this moist symmetric instability structure wa

关 键 词：天山北麓 暴雪 湿位涡 诊断 

分 类 号：P45[天文地球—大气科学及气象学]