The spatial and temporal distribution characteristics of rainstorm disaster in Sichuan Province were investigated by statistical analysis method based on 2002-2015 rainstorm disaster data of Sichuan Province. As shown...The spatial and temporal distribution characteristics of rainstorm disaster in Sichuan Province were investigated by statistical analysis method based on 2002-2015 rainstorm disaster data of Sichuan Province. As shown by the results, the rainstorm disaster in Sichuan Province was distributed mainly in four regions including Liangshan Prefecture and Sichuan Basin during 2002-2015, and the rainstorm disaster distribution had a good corresponding relationship with the rainstorm center regions;in terms of annual variation trend, the variation of rainstorm disaster frequency showed a significant quasi-2-3-year oscillation period;in terms of monthly distribution, June, July and August saw the heaviest rainstorms;the high death toll from rainstorms was attributed to not only routine rainfall, occurrence time and terrain feature, but also the populace’s awareness of disaster prevention and the disaster prevention measures they adopted. The research result has important significance to improve the pertinence and practicability of decision-making meteorological services.展开更多
为深入认识四川盆地持续性暴雨的水汽特征及来源,提高该地区暴雨预报能力,利用四川省4955个国家级及区域级自动气象站资料、全球资料同化系统(Global Data Assimilation System,GDAS)资料、欧洲中期天气预报中心(European Centre for Me...为深入认识四川盆地持续性暴雨的水汽特征及来源,提高该地区暴雨预报能力,利用四川省4955个国家级及区域级自动气象站资料、全球资料同化系统(Global Data Assimilation System,GDAS)资料、欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)第五代大气再分析资料(ERA5),基于拉格朗日方法对四川盆地2020年8月的一次持续性暴雨过程的水汽输送特征进行了分析。结果表明:强降水开始前和强降水过程中,不同起始高度层水汽输送特征有所不同。中高层起始高度(5500~10000 m),强降水开始前气团轨迹源地主要为低纬洋面,而在强降水过程中调整为地中海南岸并为盆地带来中高纬西风带干冷空气;中低层起始高度(1500~5500 m),降水过程中气团轨迹源地由地中海南岸逐渐调整为低纬洋面并为盆地带来低纬洋面暖湿空气;低层起始高度(地面至1500 m),强降水开始前轨迹源地率先调整为低纬洋面并为盆地输送比中低层更为暖湿的气流。统计不同源地水汽贡献率可知,孟加拉湾—泰国湾的水汽占主导(66.6%)、阿拉伯海次之(23.9%)、中国南海最低(9.5%)。展开更多
新一代静止气象卫星葵花8号(Himawari-8)上搭载的静止轨道成像仪AHI(Advanced Himawari Imager)凭借其高时空分辨率可以对重庆地区暴雨进行连续观测。本文选取2019年4月19日的一次区域性暴雨天气过程为试验个例,采用WRF(Weather Researc...新一代静止气象卫星葵花8号(Himawari-8)上搭载的静止轨道成像仪AHI(Advanced Himawari Imager)凭借其高时空分辨率可以对重庆地区暴雨进行连续观测。本文选取2019年4月19日的一次区域性暴雨天气过程为试验个例,采用WRF(Weather Research and Forecasting)中尺度模式进行数值模拟。基于WRFDA(Weather Research and Forecasting model Data Assimilation)同化系统对葵花8号静止气象卫星的AHI辐射率资料进行相应的质量控制和云检测,进而开展循环同化试验,考察卫星资料同化对这次强对流天气过程预报结果的改进。结果表明在同化AHI红外辐射率资料之后,辐射传输模式模拟的亮温和观测亮温更为接近。此外,AHI水汽通道辐射率资料同化有效提高了对各层高度上的风场、水汽场、雷达回波等要素特征的分析效果,并且使模式的初始条件更逼近真实的大气状态。研究发现同化AHI水汽通道辐射率资料后模拟的降水整体分布与实际情况更为接近,主要雨带位置以及强降水中心的精确程度显著高于背景场的预报效果。经过卫星同化的试验可以预报出控制试验漏报的强降水中心,并且有效地削弱了四川东部和甘肃东南部的虚假强降水范围以及强降水中心。本研究可以为川渝地区暴雨天气数值预报系统中的静止红外辐射率资料的预处理和同化应用提供有益的参考。展开更多
文摘The spatial and temporal distribution characteristics of rainstorm disaster in Sichuan Province were investigated by statistical analysis method based on 2002-2015 rainstorm disaster data of Sichuan Province. As shown by the results, the rainstorm disaster in Sichuan Province was distributed mainly in four regions including Liangshan Prefecture and Sichuan Basin during 2002-2015, and the rainstorm disaster distribution had a good corresponding relationship with the rainstorm center regions;in terms of annual variation trend, the variation of rainstorm disaster frequency showed a significant quasi-2-3-year oscillation period;in terms of monthly distribution, June, July and August saw the heaviest rainstorms;the high death toll from rainstorms was attributed to not only routine rainfall, occurrence time and terrain feature, but also the populace’s awareness of disaster prevention and the disaster prevention measures they adopted. The research result has important significance to improve the pertinence and practicability of decision-making meteorological services.
文摘为深入认识四川盆地持续性暴雨的水汽特征及来源,提高该地区暴雨预报能力,利用四川省4955个国家级及区域级自动气象站资料、全球资料同化系统(Global Data Assimilation System,GDAS)资料、欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)第五代大气再分析资料(ERA5),基于拉格朗日方法对四川盆地2020年8月的一次持续性暴雨过程的水汽输送特征进行了分析。结果表明:强降水开始前和强降水过程中,不同起始高度层水汽输送特征有所不同。中高层起始高度(5500~10000 m),强降水开始前气团轨迹源地主要为低纬洋面,而在强降水过程中调整为地中海南岸并为盆地带来中高纬西风带干冷空气;中低层起始高度(1500~5500 m),降水过程中气团轨迹源地由地中海南岸逐渐调整为低纬洋面并为盆地带来低纬洋面暖湿空气;低层起始高度(地面至1500 m),强降水开始前轨迹源地率先调整为低纬洋面并为盆地输送比中低层更为暖湿的气流。统计不同源地水汽贡献率可知,孟加拉湾—泰国湾的水汽占主导(66.6%)、阿拉伯海次之(23.9%)、中国南海最低(9.5%)。
文摘新一代静止气象卫星葵花8号(Himawari-8)上搭载的静止轨道成像仪AHI(Advanced Himawari Imager)凭借其高时空分辨率可以对重庆地区暴雨进行连续观测。本文选取2019年4月19日的一次区域性暴雨天气过程为试验个例,采用WRF(Weather Research and Forecasting)中尺度模式进行数值模拟。基于WRFDA(Weather Research and Forecasting model Data Assimilation)同化系统对葵花8号静止气象卫星的AHI辐射率资料进行相应的质量控制和云检测,进而开展循环同化试验,考察卫星资料同化对这次强对流天气过程预报结果的改进。结果表明在同化AHI红外辐射率资料之后,辐射传输模式模拟的亮温和观测亮温更为接近。此外,AHI水汽通道辐射率资料同化有效提高了对各层高度上的风场、水汽场、雷达回波等要素特征的分析效果,并且使模式的初始条件更逼近真实的大气状态。研究发现同化AHI水汽通道辐射率资料后模拟的降水整体分布与实际情况更为接近,主要雨带位置以及强降水中心的精确程度显著高于背景场的预报效果。经过卫星同化的试验可以预报出控制试验漏报的强降水中心,并且有效地削弱了四川东部和甘肃东南部的虚假强降水范围以及强降水中心。本研究可以为川渝地区暴雨天气数值预报系统中的静止红外辐射率资料的预处理和同化应用提供有益的参考。