利用多源观测资料及ERA5(ECMWF reanalysis version 5)再分析资料,从气候统计、天气分析及物理量诊断等角度,分析2023年8月2—4日黑龙江省东南部一次极端强降水过程。高空持续辐散、副热带高压和东北北部冷涡稳定少动、西南低空急流持...利用多源观测资料及ERA5(ECMWF reanalysis version 5)再分析资料,从气候统计、天气分析及物理量诊断等角度,分析2023年8月2—4日黑龙江省东南部一次极端强降水过程。高空持续辐散、副热带高压和东北北部冷涡稳定少动、西南低空急流持续水汽输送等有利条件是此次强降水过程持续时间较长的主要原因。该过程可分为两个阶段:第1阶段,经向水汽净收入层和大气饱和层深厚,大气层结为弱对流不稳定;中层受西北气流控制,低层西南急流发展、伴随弱低涡东移,形成水平风速辐合及系统性上升运动,产生大范围持续性降水;该阶段以层积混合云为主,降水效率高,个别时段伴有列车效应,造成极端小时降水量及较大累积降水量。第2阶段,经向水汽净收入集中在对流层低层,且中心强度较大,对流层低层暖湿、饱和,中高层干冷,大气具有较强对流不稳定;在中层槽和低层暖式切变的系统性抬升以及地形辐合抬升的共同作用下,局地有积云发展,引发短时强降水,降水强度分布不均。展开更多
Sea surface wind stress variabilities near and off the east coast of Korea, are examined using 7 kinds of wind datasets from measurements at 2 coastal (land) stations and 2 ocean buoys,satellite scatterometer (QuikSCA...Sea surface wind stress variabilities near and off the east coast of Korea, are examined using 7 kinds of wind datasets from measurements at 2 coastal (land) stations and 2 ocean buoys,satellite scatterometer (QuikSCAT), and global reanalyzed products (ECMWF,NOGAPS,and NCEP/NCAR). Temporal variabilities are analyzed at 3 frequency bands; synoptic (2-20 d), intra-seasonal (20-90 d),and seasonal (>90 d).Synoptic and intra-seasonal variations are predominant near and off the Donghae City due to the passage of the mesoscale weather system. Seasonal variation is caused by southeastward wind stress during Asian winter monsoon. The sea surface wind stress from reanalyzed datasets.QuikSCAT and KMA-B measurements off the coast show good agreement in the magnitude and direction,which are strongly aligned with the alongshore direction.At the land-based sites,wind stresses are much weaker by factors of 3-10 due to the mountainous landmass on the east parts of Korea Peninsula.The first EOF modes(67%-70%) of wind stresses from reanalyzed and QuikSCAT data have similar structures of the strong southeastward wind stress in winter along the coast but show different curl structures at scales less than 200 km due to the orographic effects.The second EOF modes (23%-25%) show southwestward wind stress in every September along the east coast of the North Korea展开更多
文摘利用多源观测资料及ERA5(ECMWF reanalysis version 5)再分析资料,从气候统计、天气分析及物理量诊断等角度,分析2023年8月2—4日黑龙江省东南部一次极端强降水过程。高空持续辐散、副热带高压和东北北部冷涡稳定少动、西南低空急流持续水汽输送等有利条件是此次强降水过程持续时间较长的主要原因。该过程可分为两个阶段:第1阶段,经向水汽净收入层和大气饱和层深厚,大气层结为弱对流不稳定;中层受西北气流控制,低层西南急流发展、伴随弱低涡东移,形成水平风速辐合及系统性上升运动,产生大范围持续性降水;该阶段以层积混合云为主,降水效率高,个别时段伴有列车效应,造成极端小时降水量及较大累积降水量。第2阶段,经向水汽净收入集中在对流层低层,且中心强度较大,对流层低层暖湿、饱和,中高层干冷,大气具有较强对流不稳定;在中层槽和低层暖式切变的系统性抬升以及地形辐合抬升的共同作用下,局地有积云发展,引发短时强降水,降水强度分布不均。
文摘Sea surface wind stress variabilities near and off the east coast of Korea, are examined using 7 kinds of wind datasets from measurements at 2 coastal (land) stations and 2 ocean buoys,satellite scatterometer (QuikSCAT), and global reanalyzed products (ECMWF,NOGAPS,and NCEP/NCAR). Temporal variabilities are analyzed at 3 frequency bands; synoptic (2-20 d), intra-seasonal (20-90 d),and seasonal (>90 d).Synoptic and intra-seasonal variations are predominant near and off the Donghae City due to the passage of the mesoscale weather system. Seasonal variation is caused by southeastward wind stress during Asian winter monsoon. The sea surface wind stress from reanalyzed datasets.QuikSCAT and KMA-B measurements off the coast show good agreement in the magnitude and direction,which are strongly aligned with the alongshore direction.At the land-based sites,wind stresses are much weaker by factors of 3-10 due to the mountainous landmass on the east parts of Korea Peninsula.The first EOF modes(67%-70%) of wind stresses from reanalyzed and QuikSCAT data have similar structures of the strong southeastward wind stress in winter along the coast but show different curl structures at scales less than 200 km due to the orographic effects.The second EOF modes (23%-25%) show southwestward wind stress in every September along the east coast of the North Korea
