辽东半岛南部冷流降雪的统计特征及相关要素分析  

Analysis on the Statistical Characteristics and the Related Factors of Cold-Airflow Snowfall in the Southern Part of Liaodong Peninsula

作　　者：于亚鑫 阎琦[1] 张萌萌 杨瑞雯 YU Yaxin;YAN Qi;ZHANG Mengmeng;YANG Ruiwen(Liaoning Meteorological Observatory,Shenyang 110166,China;Liaoning Provincial Meteorological Service Center,Shenyang 110166,China)

机构地区：[1]辽宁省气象台,辽宁沈阳110166 [2]辽宁省气象服务中心,辽宁沈阳110166

出　　处：《海洋技术学报》2023年第2期77-86,共10页Journal of Ocean Technology

基　　金：国家重点研发计划资助项目(2018YFC1507305);中国气象局预报员专项项目(CMAYBY2019-024)。

摘　　要：辽东半岛南部地区及周边海域在特定的季节、天气形势和条件下可能会造成灾害性的冷流降雪天气,提高冷流降雪预报准确性,对沿海地区防灾减灾具有重要意义。本文利用1981-2021年辽宁地区各气象站逐日降水资料及ERA5再分析资料,运用统计学和物理量诊断方法对辽东半岛南部地区冷流降雪的气候特征、发生规律及成因进行了分析。研究结果表明:辽东半岛南部地区冷流降雪强度弱,主要以小雪为主;降雪次数和降雪量均呈现南多北少的特点,前者年际变化趋势平稳而后者较大;12月是冷流降雪发生的主要月份,而11月和2月是降雪强度较强的月份。冷流降雪的产生和较大的海洋表面与大气温差、低层不稳定层结、海陆地形作用有密切关系;当500 hPa和850 hPa影响系统为冷涡或低槽、辽东半岛南部及周边海域低层为偏北风且相对湿度条件较好、1000 hPa对应正相对涡度等条件时,可以预测辽东半岛南部可能出现冷流降雪;海表温度(Sea Surface Temperature,SST)与850 hPa温度之差直接决定了地面冷流降雪量的大小。Cold-airflow snowfall in the southern part of the Liaodong Peninsula and its adjacent sea area may cause disastrous weather under the specific season,weather situations and conditions.In this case,improving the accuracy of cold-airflow snowfall forecast is of great significance to disaster prevention and mitigation in coastal areas.Using the daily precipitation data of each meteorological station in Liaoning and ERA5 reanalysis data from 1981 to 2021,this paper uses statistical and physical quantity diagnostic methods to analyze the climatic characteristics,causes and regularities of cold-airflow snowfhll in the southern part of the Liaodong Peninsula.The results show that the intensity of snowfall in the southern part of the Liaodong Peninsula is weak,and it is mainly light snow.The number and the amount of cold-airflow snowfall are both more in the south and less in the north,and the former inter-annual variation is stable while the latter is obvious.The cold-airflow snowfall often occurs in December,while with stronger snowfall intensity in November and February.The generation of cold-airflow snowfall is closely related to the large air-sea temperature difference,unstable stratification in the lower layer,and the effect of sea-land topographic condition.In addition,when the influencing systems are cold eddy and low trough on the 500 hPa and 850 hPa weather charts,the lower layer is northerly wind with good relative humidity,and 1000 hPa corresponds to positive relative vorticity in the southern part of the Liaodong Peninsula and its adjacent sea area,it can be predicted that cold-airflow snowfall may occur in the southern part of the Liaodong Peninsula.Whafs more,the correlation coefficient further indicates that the difference between sea surface temperature and 850 hPa temperature directly determines the magnitude of cold-airflow snowfall.

关 键 词：辽东半岛南部 冷流降雪 气候特征 海表温度 海陆地形 要素 

分 类 号：P47[天文地球—大气科学及气象学]