“23·12”山东半岛特大海效应暴雪特征及成因  

Characteristics and causes of“23·12”extremely severe sea-effect snowstorm in Shandong Peninsula

作　　者：杨成芳 戈瑶[2] 刘畅 周成[2] 冯桂力 YANG Chengfang;GE Yao;LIU Chang;ZHOU Cheng;FENG Guili(Key Laboratory for Meteorological Disaster Prevention and Mitigation of Shandong,Jinan 250031,China;Shandong Meteorological Observatory,Jinan 250031,China;Shandong Institute of Meteorological Sciences,Jinan 250031,China)

机构地区：[1]山东省气象防灾减灾重点实验室,山东济南250031 [2]山东省气象台,山东济南250031 [3]山东省气象科学研究所,山东济南250031

出　　处：《海洋气象学报》2024年第2期1-14,共14页Journal of Marine Meteorology

基　　金：山东省自然科学基金项目(ZR2022MD095,ZR2023MD025);山东省气象局大城市气象服务关键技术创新团队项目(SDCXTD2023-1)。

摘　　要：采用地面气象观测站、多普勒天气雷达、闪电、积雪深度人工加密观测资料、常规观测及欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)第五代大气再分析(ECMWF Reanalysis v5,ERA5)资料,对2023年12月15—22日山东半岛特大海效应暴雪过程的降雪特征及极端性成因进行了分析。结果表明:(1)此次过程有4站积雪深度突破本站历史极值,有1站2 d的日降雪量为山东半岛海效应降雪有气象记录以来的最大值,文登积雪深度达74 cm,超过山东所有国家级地面气象观测站纪录,是一次极端海效应暴雪事件。(2)欧亚中高纬度阻塞形势下两次异常强冷空气持续影响渤海和山东半岛地区,850 hPa温度最低降至-21~-20℃,冷空气强度明显强于往年12月海效应暴雪过程,造成降雪持续时间长、累计降雪量大。异常强冷空气是此次极端暴雪过程产生的关键因素,渤海海面温度(简称“海温”)异常偏高是有利的海温背景。(3)冷空气强、海温偏高造成海气温差偏大,700 hPa以下产生对流不稳定,使得降雪强度大;强降雪发生在海气温差快速增大阶段。(4)925 hPa以下存在来自渤海的北—东北风与内陆地区的西北风构成的切变线,产生强上升运动,切变线长时间维持形成“列车效应”。(5)主要降雪时段强垂直上升运动、高相对湿度层的温度为-20~-12℃,适宜树枝状冰晶形成和维持,有利于产生大的积雪和降雪含水比;2 m气温持续低于-5℃,0 cm地温在降雪开始时即降至0℃以下,且两次强降雪过程仅间隔1 d,均有利于降雪累积产生极端积雪深度。Based on the data of meteorological observation stations and Doppler weather radars,lighting data,artificial intensive snow depth observations,conventional observations,and ECMWF(European Centre for Medium-Range Weather Forecasts)Reanalysis v5(ERA5),the characteristics and causes of the extremely severe sea-effect snowstorm over Shandong Peninsula from 15 to 22 December 2023 are analyzed.The main results are as follows.(1)The snow depth of 4 stations exceeds historical records and the daily snowfall of one station in 2 d tops the records of sea-effect snowfall over Shandong Peninsula.The snow depth of 74 cm in Wendeng exceeds the records of all meteorological observation stations in Shandong,so it is an extreme sea-effect snowstorm event.(2)The two abnormally strong cold air processes under the blocked circulation in middle and high latitudes over Eurasia continuously affect the Bohai Sea and Shandong Peninsula,and the temperature of 850 hPa drops to the range between-21 and-20℃.The cold air is significantly stronger than that of the sea-effect snowstorms in December of previous years,resulting in a long duration of snowfall and a large amount of accumulated snowfall.The abnormally strong cold air is the fundamental reason for the extreme snowfall process,and the abnormally high SST(sea surface temperature)over the Bohai Sea is a favorable background.(3)The strong cold air and higher SST lead to larger air-sea temperature difference and unstable convection below 700 hPa,which causes high snowfall intensity,and the heavy snowfall occurs in the stage when the air-sea temperature difference increases rapidly.(4)There is a shear line composed of northerly-northeasterly from the Bohai Sea and northwesterly from inland areas below 925 hPa,which produces a strong ascending motion,and the shear line’s maintaining contributes to the formation of train effect.(5)During the main snowfall period,the temperature in the layer of strong vertical ascending motion and high relative humidity lies between-20 and-12℃,which is

关 键 词：特大海效应暴雪 强冷空气 海温异常 积雪深度 

分 类 号：P426.631[天文地球—大气科学及气象学] P468.025