为研究云降水物理过程对四川盆地东北部暴雨的影响,利用FNL(final operational global analysis)全球分析资料和WRF(weather research and forecasting)模式4.3版对2022年10月4—5日发生的一次典型强降水过程进行云微物理方案敏感性试验...为研究云降水物理过程对四川盆地东北部暴雨的影响,利用FNL(final operational global analysis)全球分析资料和WRF(weather research and forecasting)模式4.3版对2022年10月4—5日发生的一次典型强降水过程进行云微物理方案敏感性试验,并与CMPAS(China Meteorological Administration multi-source merged precipitation analysis system)融合降水数据、GPM(global precipitation measurement)卫星探测产品进行对比分析。结果表明,6种微物理方案对川东北的降水范围模拟较好,雨带呈东北-西南走向,但强度偏弱,Lin和WSM6方案模拟出了强降水中心,空间分布与降水实况大致相同。Lin、WSM6和WDM6方案模拟的云场分布和强度最接近GPM卫星观测值,6种微物理方案对雨水含量的模拟最好,对云水和冰水含量的模拟呈现低估。云水、雨水和冰水在垂直方向上的匹配程度是此次模式预报差异产生的原因;另外,不同方案模拟的云微物理结构上的差异,以及各类水成物粒子的含量和分布是否有利于雪、霰粒子的生成及增长也是预报差异产生的重要原因;WSM6方案模拟的水成物在空间上更加匹配,模拟的降水极值更接近观测值,模拟效果相对较好。展开更多
基于2005—2021年青海省夏季逐小时站点观测数据,从不同时间尺度、日变化、海拔等多角度对中国气象局陆面数据同化系统(China Meteorological Administration Land Data Assimilation System,CLDAS)与全球降水测量数据(Global Precipita...基于2005—2021年青海省夏季逐小时站点观测数据,从不同时间尺度、日变化、海拔等多角度对中国气象局陆面数据同化系统(China Meteorological Administration Land Data Assimilation System,CLDAS)与全球降水测量数据(Global Precipitation Measurement,GPM)进行准确性评估,结果表明:CLDAS总体优于GPM。CLDAS与GPM降水产品均倾向于高估弱降水的降水量和降水频率,低估强降水的降水量和降水频率。CLDAS对降水量、降水频率日变化特征及不同海拔的评估准确性表现均优于GPM,但在湖泊群附近存在异常大值。随着海拔升高,CLDAS与GPM的降水量和降水频率与海拔的相关性均逐渐增强,且CLDAS的相关性上升趋势更为显著。GPM则表现出高估低海拔地区的降水量和降水频率,低估高海拔地区的降水量和降水频率的特点。展开更多
The North Pacific storm track(NPST)is a high-frequency area of extratropical cyclones and an important channel for water vapor and energy transfer between low and mid–high latitudes.Previous weather and dynamic studi...The North Pacific storm track(NPST)is a high-frequency area of extratropical cyclones and an important channel for water vapor and energy transfer between low and mid–high latitudes.Previous weather and dynamic studies in this region have made significant progress,but due to the lack of ocean surface rainfall observation data,there is a lack of statistical research on precipitation in this area.In this study,statistical research on the spatiotemporal distribution characteristics of NPST rainfall was conducted based on GPM DPR(Global Precipitation Measurement Dual-frequency Precipitation Radar)observation data and ERA5 atmospheric parameters,and analysis and explanations are provided based on the atmospheric parameters.The study found that,compared to low-pressure systems,pressure gradients have a greater impact on cyclone activity and rainfall distribution.This feature,along with the meridional distribution of high atmospheric water vapor in the North Pacific Ocean and low in the north,collectively leads to the offset of high-frequency rainfall areas relative to storm tracks.The distribution of sea surface temperatures in the North Pacific Ocean affects the zonal distribution of storm tracks,causing weather disturbances and precipitation along the storm tracks to exhibit a northward extension from west to east.This study deepens our understanding of the role of NPST in global-scale water vapor and energy balance,and is of great significance for improving the prediction accuracy of climate models with respect to rainfall generated by extratropical cyclones.展开更多
文摘基于2005—2021年青海省夏季逐小时站点观测数据,从不同时间尺度、日变化、海拔等多角度对中国气象局陆面数据同化系统(China Meteorological Administration Land Data Assimilation System,CLDAS)与全球降水测量数据(Global Precipitation Measurement,GPM)进行准确性评估,结果表明:CLDAS总体优于GPM。CLDAS与GPM降水产品均倾向于高估弱降水的降水量和降水频率,低估强降水的降水量和降水频率。CLDAS对降水量、降水频率日变化特征及不同海拔的评估准确性表现均优于GPM,但在湖泊群附近存在异常大值。随着海拔升高,CLDAS与GPM的降水量和降水频率与海拔的相关性均逐渐增强,且CLDAS的相关性上升趋势更为显著。GPM则表现出高估低海拔地区的降水量和降水频率,低估高海拔地区的降水量和降水频率的特点。
文摘新一代全球卫星降水产品GPM(Global Precipitation Measurement)为降雨观测提供了新的途径。以淮河上游王家坝流域为研究区,以地面实测降雨数据为基准,空间上从点、面尺度,时间上从日、月尺度综合评价了GPM卫星降水数据的精度,并结合分布式的SWAT(Soil and Water Assessment Tool)模型评估了GPM用于水文模拟的适用性,以探究GPM卫星降水数据对地面实测降水数据的可替代性。结果显示:(1)从日尺度聚合到月尺度、从点尺度平均到面尺度,GPM的降雨精度逐渐提高,在面尺度上统计月尺度GPM降雨具有最高的精度(相关系数CC=0.95,均方根误差RMSE=1.10 mm,平均绝对误差MAE=0.79 mm);(2) GPM整体上表现出对实测降雨的高估(相对误差BIAS为17.50%~24.14%),高估主要发生在低降雨强度事件和降雨相对不充足的非汛期,对高强度降雨和汛期的降雨估算精度较高,河源山区和淮河干流以南的湿润地区因降雨量大GPM精度高;(3)当采用静态参数法(沿用地面实测降雨率定的SWAT模型参数)时,GPM驱动的日尺度SWAT模型模拟精度出现了严重的退化,但是月尺度的SWAT模型仍然能保持可靠的精度;(4)当采用动态参数法(基于GPM降雨重新率定SWAT模型参数)时,GPM驱动的SWAT模型在日尺度和月尺度上的模拟精度均能得到保证。研究结果表明,GPM虽然对日降雨过程的刻画不准确,但在月降雨总量的估算上精度较高,因此GPM在月尺度的水文模拟上能够基本替代地面实测降雨数据。此外,对于无降雨资料的地区,基于GPM历史数据率定水文模型参数用于水文模拟具有更好的适用性。
基金funded by the National Natural Science Foundation of China(Grant Nos.42275140,42230612,91837310,41675041,and 92037000)the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(Grant No.2019QZKK0104)。
文摘The North Pacific storm track(NPST)is a high-frequency area of extratropical cyclones and an important channel for water vapor and energy transfer between low and mid–high latitudes.Previous weather and dynamic studies in this region have made significant progress,but due to the lack of ocean surface rainfall observation data,there is a lack of statistical research on precipitation in this area.In this study,statistical research on the spatiotemporal distribution characteristics of NPST rainfall was conducted based on GPM DPR(Global Precipitation Measurement Dual-frequency Precipitation Radar)observation data and ERA5 atmospheric parameters,and analysis and explanations are provided based on the atmospheric parameters.The study found that,compared to low-pressure systems,pressure gradients have a greater impact on cyclone activity and rainfall distribution.This feature,along with the meridional distribution of high atmospheric water vapor in the North Pacific Ocean and low in the north,collectively leads to the offset of high-frequency rainfall areas relative to storm tracks.The distribution of sea surface temperatures in the North Pacific Ocean affects the zonal distribution of storm tracks,causing weather disturbances and precipitation along the storm tracks to exhibit a northward extension from west to east.This study deepens our understanding of the role of NPST in global-scale water vapor and energy balance,and is of great significance for improving the prediction accuracy of climate models with respect to rainfall generated by extratropical cyclones.
