长江中游2020年梅雨期两种大气再分析产品日变化特征再现能力分析  

Analysis on reproducing ability of diurnal variation characteristics of two atmospheric reanalysis products in the middle reaches of the Yangtze River during the Meiyu period in 2020

作　　者：郭英莲 李红莉[1] 王珏[1] 冷亮[1] 王明欢[1] GUO Yinglian;LI Hongli;WANG Jue;LENG Liang;WANG Minghuan(Hubei Key Laboratory for Heavy Rain Monitoring and Warning Research,Institute of Heavy Rain,CMA,Wuhan 430205)

机构地区：[1]中国气象局武汉暴雨研究所暴雨监测预警湖北省重点实验室,武汉430205

出　　处：《暴雨灾害》2022年第6期691-700,共10页Torrential Rain and Disasters

基　　金：第二次青藏高原综合科学考察研究项目(2019QZKK0105);湖北省气象局科技基金项目(2020Z05,2020Q02,2021Y05);中国气象局创新发展专项(CXFZ2021Z081,CXFZ2022J010)。

摘　　要：利用逐小时地面、风廓线和天气雷达观测资料,对局地分析与预报系统的再分析产品(Local Analysis and Prediction System-Live Products, Laps_Live)和欧洲中期天气预报中心的第五代再分析产品(The fifth Generation ECMWF Reanalysis, ERA5)在2020年梅雨期的日变化特征进行检验和分析。结果表明:LAPS_LIVE地面要素日变化与实况的相关性普遍比ERA5高。LAPS_LIVE对武陵山区地面温、湿度日变化再现能力不如ERA5,对大别山区海平面气压和地面温、湿度的日变化再现能力明显优于ERA5。两种再分析资料在江汉平原区的海平面气压和地面温、湿度的日变化均与实况误差很小。LAPS_LIVE地面平均风场的误差比ERA5小,但风场日变化幅度明显偏小、风速偏低;ERA5地面风场的日变化幅度和风速则比实况显著偏强。LAPS_LIVE低空风廓线的惯性振荡特征与观测一致,对上午时段低层风场的时间演变和垂直切变的再现能力强于ERA5,但对夜间低空急流的再现能力不足。ERA5低空风场高估上午时段的偏北风和凌晨时段的西南低空急流,但ERA5的低空风廓线平均场比LAPS_LIVE更接近探测值。Using hourly ground observation, wind profile observation and weather radar observation, the diurnal variation characteristics of the reanalysis products of the Local Analysis and Forecasting System(LAPS_LIVE) and the fifth-generation reanalysis product of the European Centre for Medium-Range Weather Forecasts(ERA5) during the Meiyu period in 2020 were validated and analyzed. The results show that the correlation between the diurnal variations of surface fields in LAPS_LIVE and ground truth is higher than that in ERA5 overall. Specifically, LAPS_LIVE is not as good as ERA5 in terms of the diurnal variations of surface temperature and humidity in southwest mountainous area. LAPS_LIVE is obviously better than ERA5 in terms of the diurnal variations of sea level pressure and surface temperature and humidity in the Dabie Mountains area. The diurnal variations of sea level pressure and surface temperature and humidity in the Jianghan Plain have small biases for both reanalysis datasets. The bias of mean surface wind field in LAPS_LIVE is smaller than that in ERA5, but the diurnal variation in LAPS_LIVE is weaker and the wind speed is also lower. The diurnal amplitude and mean speed of surface wind in ERA5 are significantly stronger than the observations. The inertial oscillation characteristics of low-level wind profile in LAPS_LIVE are consistent with the observations. The time evolution and vertical shear of low-level wind field in the morning in LAPS_LIVE is better than that in ERA5, but the low-level jet at night in LAPS_LIVE is worse. ERA5 overestimates the low-level northerly winds and the southwest jet in the morning, but its average low-level wind field is closer to the observations than LAPS_LIVE.

关 键 词：梅雨期 再分析产品 日变化 LAPS ERA5 

分 类 号：P456.7[天文地球—大气科学及气象学]