摘要
利用2007-2020年的常规观测、东北地区6 h和24 h降水资料以及欧洲中期天气预报中心ERA5再分析资料,对东北地区温带气旋暴雪过程有/无大气河伴随进行了统计,并对比了有/无大气河伴随时环境场特征的异同。结果表明:83%的温带气旋暴雪过程有大气河伴随,其中59%的大气河登陆东北。11月和3月的暴雪过程大气河出现的频率最高,12月和1月基本无大气河伴随。南方气旋和黄淮气旋参与的暴雪过程大气河出现的频率高且强度强,相应的降水量较大;蒙古气旋暴雪过程大气河出现的频率低,降水量较小。有大气河伴随的暴雪过程高空急流有2支,低空急流强;500 hPa上有冷涡,形成切断低压和大气河相互作用有利于强降水的形势;850 hPa有明显的暖舌和较强锋区,因而有利于水汽输送和动力抬升,主要为冷锋降雨和暖锋降雪。无大气河相伴的暴雪过程高空急流有1支,低空急流弱;500 hPa上无冷涡,西风槽较弱;850 hPa锋区和低涡强度较弱,高空辐散和水汽条件差,主要为暖锋降雪。有大气河伴随时暴雪过程的水汽主要源自东海和黄渤海,低层不稳定层较厚,边界层水汽辐合区宽广且强,上升运动较强;无大气河伴随时水汽主要源自日本海,不稳定层结和上升运动较弱,边界层水汽辐合区狭窄且弱。大气河不仅体现了强水汽输送,还体现了较好的动力抬升。
A statistical study on snowstorms in northeastern China caused by extratropical cyclones with and without the support of atmospheric rivers(ARs)was conducted using conventional observations,6-hour and 24-hour precipitation data,as well as ERA5 reanalysis data from the European Center for Medium-Range Weather Forecasts from 2007 to 2020.In addition,the environmental fields in snowstorms with and without ARs support were compared.According to the findings,ARs occurred in 83 percent of snowstorms associated with extratropical cyclones,with 59%of ARs landing in northeastern China.ARs were most common in November and March,with nearly no ARs in December and January.On the one hand,the frequency and intensity of ARs were high during the snowstorms involving the southern and Huanghuai cyclones,and the associated precipitation was heavy.Snowstorms associated with Mongolia cyclones,on the other hand,had a low frequency of ARs and light precipitation.There were two branches of upper-level jets and strong low-level jets for the snowstorms with ARs.And a cold vortex was located at 500 hPa,forming the interaction between the cut-off low and the ARs,which was conducive to heavy rainfall.An obvious warm tongue and strong frontal zones were located at 850 hPa,which was favorable for water vapor transport and dynamic lifting with the support of ARs.And then it rained associated with the cold front and snowed associated with the warm front during snowstorms accompanied by ARs.Compared with snowstorms accompanied by ARs,there was one branch of upper-level jets and weak low-level jets for the snowstorms without ARs.And there was no cold vortex and a weak westerly trough at 500 hPa.The frontal zones and low vortex were weak at 850 hPa without the support of ARs.The upper-level divergence was weak and water vapor was poor,and it mostly snowed associated with the warm front in snowstorm events without ARs support.Water vapor during snowstorms with the support of ARs originated from the East China Sea,the Yellow and Bohai Seas,and the w
作者
黄子怡
赵宇
李树岭
白云飞
HUANG Ziyi;ZHAO Yu;LI Shuling;BAI Yunfei(Key Laboratory of Meteorological Disaster,Ministry of Education/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/International Joint Laboratory on Climate and Environment Change,Nanjing University of Information Science&Technology,Nanjing 210044,Jiangsu,China;Harbin Meteorological Bureau,Heilongjiang Province,Harbin 150030,Heilongjiang,China)
出处
《高原气象》
CSCD
北大核心
2023年第3期734-747,共14页
Plateau Meteorology
基金
国家自然科学基金面上项目(41975055)
国家重点研发计划项目(2017YFC1502002)。
关键词
温带气旋
暴雪过程
大气河
合成分析
Extratropical cyclone
snowstorm
atmospheric river
composite analysis
