铁岭市东北冷涡短时强降水的时空特征及预报物理量分析
Spatio-temporal characteristics and analysis of forecast physical quantities of short-duration heavy rain in Tieling caused by Northeast Cold Vortex
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摘要: 为精细研究铁岭市短时强降水的时空分布特征,提高短时强降水的潜势预报能力,基于逐小时国家气象站和区域自动站降水资料以及ERA5再分析资料,对比冷涡和非冷涡短时强降水的时空分布特征,并对可预报冷涡短时强降水的物理量进行分析。结果表明:冷涡短时强降水(Cold vortex short-duration heavy rain,CV_SDHR)多发地集中在中部平原地区;非冷涡短时强降水(Non-cold vortex short-duration heavy rain,non-CV_SDHR)在平原西部、山区的东部和南部出现较多。两类短时强降水出现站次的空间分布在各月存在明显差异,CV_SDHR主要集中区从6—9月呈自北向南移动。两类短时强降水站次呈缓慢上升趋势。CV_SDHR站次7月达到峰值,non-CV_SDHR在8月达到峰值。CV_SDHR主要发生在下午至前半夜。CV_SDHR与non-CV_SDHR各物理量大小存在月际差异,925、850、700 hPa比湿、整层可降水量、850 hPa和500 hPa假相当位温差均为7月最高、8月次之。对比CV_SDHR与non-CV_SDHR各物理量25百分位数在各月的差异,得到铁岭市CV_SDHR各月物理量阈值。Abstract: In order to finely study the spatio-temporal distribution characteristics of short-duration heavy rain in Tieling and improve the potential forecasting ability of short-duration heavy rain,hourly precipitation data from national meteorological stations and regional automatic stations,as well as ERA5 reanalysis data were used to compare the spatio-temporal distribution characteristics of northeast cold vortex and non-northeast cold vortex short-duration heavy rain and analyze the physical quantities of predictable short-duration heavy rain in cold vortex.The results show that cold vortex short-duration heavy rain (CV_SDHR) is mainly concentrated in the central plains.Non cold vortex short-duration heavy rain (non-CV_SDHR) is mainly concentrated in the western plains,eastern and southern mountainous areas.The spatial distributions of two types of short-duration heavy rain stations show significant differences in each month.The main concentration areas of CV_SDHR move from north to south from June to September.Two types of short-duration heavy rain stations show slow a upward trend.CV_SDHR reaches its peak in July and non-CV_SDHR reaches its peak in August.CV_SDHR mainly occurs from the afternoon to the first half of the night.There are differences in the distribution of physical quantities between CV_SDHR and non-CV_SDHR in each month.The specific humidity at 925,850,and 700 hPa,the total precipitable water,and the pseudo-equivalent temperature difference between 850 hPa and 500 hPa are higher in July,and second in August.Compare the differences in the 25th percentile of physical quantities between CV_SDHR and non-CV_SDHR in each month,and obtain the monthly physical quantity thresholds for CV_SDHR in Tieling.
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