摘要
利用2013—2021年暖季(6—9月)京津冀地区逐时降水资料和ERA5再分析资料,根据天气形势对短时强降水进行天气学分型,统计短时强降水发生的时空特征,对比动力、水汽和热力不稳定条件等环境要素特征。结果表明:短时强降水以冷涡型和副高型为主,占到55%,且主要发生在7月中下旬到8月上中旬,强降水主要集中在下午到前半夜。对比发现,不同类型短时强降水空间分布特征区别明显,分型合理;各类型大多表现为低层辐合和高层辐散,西南涡型动力强度表现最强,且随降水临近是增加的,弱天气强迫型在降水前各个时段动力表现最弱;副高型、台风型和西南涡型水汽最为充沛,副高型925 hPa比湿中位数达到19.14 g·kg~(-1),西南涡型在高低层相对湿度均较大,低层平均相对湿度中位数达到87%,弱天气强迫型相对较差,为74%,各类型整层大气可降水量在降水前随时间基本是增加的;弱天气强迫型的热力不稳定性最为突出,850 hPa和500 hPa温度差中位数最大为25.74℃,西南涡型最小,除弱天气强迫型外,各类型热力条件随时间是减弱的。
Based on the hourly precipitation data and the fifth-generation European Center for Medium-Range Weather Forecasts(ECMWF)atmospheric reanalysis(ERA5)data in Beijing-Tianjin-Hebei region in the warm season(June-September)from 2013 to 2021,the temporal and spatial characteristics were statistically analyzed.The evolution characteristics of environmental factors such as dynamic,water vapor,and thermal instability conditions of different synoptic patterns were compared and analyzed.The results show that the Subtropical High(SH)pattern and the Cold Vortex(CV)pattern are the main types of short-duration heavy rainfall,accounting for 55%.The short-duration heavy rainfall mainly occurs from the middle and late July to the early and middle August and concentrates from the afternoon to the midnight.Comparably,the rain distribution differences are obvious.Pattern parting is reasonable.Mostly for low-level convergence and high-level divergence,the Southwest Vortex(SV)pattern are the most prominent,and increase with approaching precipitation,while the Weak Weather(WW)pattern is the smallest in all stages.The water vapor of the SH pattern,the Typhoon Wind(TW)pattern and the SV pattern are the most abundant,median specific humidity on 925 hPa is 19.14 g·kg-1 for SH pattern.The SV pattern has the highest saturation in high and low layers,and the average of median relative humidity reaches 87%in low layers.The WW pattern is relatively low of 74%.The precipitable water vapor of almost all patterns increases with the approaching precipitation.The thermal instability of the WW patter is the strongest,and the median temperature difference on 825 hPa and 500 hPa reaches 25.74℃,while the SV pattern is the weakest.The thermal condition of each type weakens over time except for the WW pattern.
作者
申莉莉
李江波
王秀明
钟琦
李文晴
孙卓
SHEN Lili;LI Jiangbo;WANG Xiuming;ZHONG Qi;LI Wenqing;SUN Zhuo(Key Laboratory of Meteorology and Ecological Environment of Hebei Province,Shijiazhuang 050021,China;Xiong’an Atmospheric Boundary Layer Key Laboratory,CMA,Xiong’an 071800,China;Meteorological Disaster Prevention and Environment Meteorological Center of Hebei Province,Shijiazhuang 050021,China;Hebei Meteorological Observatory,Shijiazhuang 050021,China;China Meteorological Administration Training Centre,Beijing 100081,China;Public Meteorological Service Centre of Hebei Province,Shijiazhuang 050021,China)
出处
《气象与环境学报》
2024年第1期37-46,共10页
Journal of Meteorology and Environment
基金
中国气象局创新发展专项(CXFZ2023J012)
中国气象局复盘总结专项(FPZJ2023-170)
河北省气象局灾害性天气机理研究创新团队
环渤海区域科技协同创新基金项目(QYXM202006)
河北省重点研发计划项目(23375401D)共同资助。
关键词
短时强降水
分型
环境条件
Short-duration heavy rainfall
Typing
Environmental conditions
