摘要
针对2009—2017年6—9月天津地区140次短时强降水天气过程,将NCEP FNL(1°×1°)全球分析资料与地面气象观测数据融合,计算天津地区短时强降水的环境物理量参数,通过偏差和偏差区间占有率等分析融合环境物理量的可信度,并在大量样本统计基础上给出不同月份的短时强降水环境参量特征和指标。结果表明:(1)基于NCEP FNL分析资料与地面气象观测数据融合的环境物理量在短时强降水潜势判断中具有较高的可信度,融合CAPE、LI、LCL平均绝对误差分别为260.7 J/kg、0.9℃、14 hPa,与融合前的NCEP FNL物理量相比绝对误差分别降低了58.1%、48.0%、49.0%。(2)不同月份短时强降水发生所必需的水汽、热力和能量等环境条件差异显著,TPW、K、LI、CAPE、LCL和Z0均呈现明显的月变化特征。(3)若以75%短时强降水发生的环境条件作为预报指标,7—8月TPW、K、CAPE、Z0、LCL物理量阈值极为相近,短时强降水多发生在TPW>45 kg/m2、K>32℃、CAPE>835 J/kg、LCL>882 hPa、Z0>4300 m条件下,6月物理量指标要求明显降低,如TPW>34 kg/m2、K>30℃、CAPE>353 J/kg、LCL>880 hPa、Z0>3900 m,9月预报指标要求则最低。
Based on the data fusion of NCEP FNL(1°×1°)global analysis and surface meteorological observations,the environmental parameters is calculated for the 140 short-duration heavy rainfall events in Tianjin between June and September from 2009 to 2017.And the quality of the merging environmental parameters is also assessed to confirm its reliability in terms of the deviation with actual parameters and the deviation occupancy in different ranges.Finally,the statistical analysis is performed to explore the environmental parameter characteristics for short-duration heavy rainfall,and the prediction indexes are established as well.The results show that:(1)The environmental parameters based on the data fusion are more reliable than only based on NCEP FNL analysis data for short-duration heavy rainfall in Tianjin.The mean absolute errors of the merging CAPE,LI and LCL have been reduced to 260.7 J/kg,0.9℃and 14 hPa separately,which are 58.1%,48.0%and 49.0%lower than before merging.(2)The environmental conditions for short-duration heavy rainfall,such as moisture,thermal and energy,have significant differences in different months,and the parameters(TPW,K,LI,CAPE,LCL and Z0)show monthly variations similarly.(3)Taking 75%short-duration heavy rainfalls happening as prediction indexes,the parameter thresholds of TPW,K,LI,CAPE,LCL,Z0 are almost the same in July and August,most short-duration heavy rainfalls occur in the condition of TPW>45 kg/m2,K>32℃,CAPE>835 J/kg,LCL>882 hPa,Z0>4300 m.However,the parameter thresholds in June are significantly lower than in July and August with TPW>34 kg/m2,K>30℃,CAPE>353 J/kg,LCL>880 hPa,Z0>3900 m,and the parameter thresholds in September are the lowest.
作者
尉英华
王艳春
朱磊磊
林晓萌
杨洋
WEI Yinghua;WANG Yanchun;ZHU Leilei;LIN Xiaomeng;YANG Yang(Tianjin Meteorological Observatory,Tianjin 300074,China;Tianjin Meteorological Bureau,Tianjin 300074,China)
出处
《沙漠与绿洲气象》
2020年第5期84-91,共8页
Desert and Oasis Meteorology
基金
国家自然科学基金项目(41575049)
中国气象局预报员专项(CMAYBY2020-008)
天津市气象局项目(202013zdxm06)。
关键词
短时强降水
环境物理量
融合
可信度
short-duration heavy rainfall
environmental parameters
data fusion
confidence
