The Yangtze–Huai River Basin(YHRB)always suffers from anomalously heavy rainfall during the warm season,and has been well explored as a whole area during the past several decades.In this study,the YHRB is divided int...The Yangtze–Huai River Basin(YHRB)always suffers from anomalously heavy rainfall during the warm season,and has been well explored as a whole area during the past several decades.In this study,the YHRB is divided into two core regions-the northern YHRB(nYHRB)and southern YHRB(sYHRB)-based on 29-year(1979–2007)June–July–August(JJA)temporally averaged daily rainfall rates and the standard deviation of rainfall.A spectral analysis of JJA daily rainfall data over these 29 years reveals that a 3–7-day synoptic-timescale high-frequency mode is absolutely dominant over the nYHRB,with 10–20-day and 15–40-day modes playing a secondary role.By contrast,3–7-day and 10–20-day modes are both significant over the sYHRB,with 7–14-day,15–40-day,and 20–60-day modes playing secondary roles.Based on a comparison between bandpass-filtered rainfall anomalies and original rainfall series,a total of 42,1,5,and 3 heavy rainfall events(daily rainfall amounts in the top 5%of rainy days)are detected over the nYHRB,corresponding to 3–7-day,7–14-day,10–20-day,and 15–40-day variation disturbances.Meanwhile,a total of 28,8,12,and 6 heavy rainfall events are detected over the sYHRB,corresponding to 3–7-day,7–14-day,10–20-day,and 20–60-day variation disturbances.The results have important implications for understanding the duration of summer heavy rainfall events over both regions.展开更多
在雨中舰载激光武器和激光雷达的工作效能受到制约。因此,研究激光在降水中的衰减特性对军事行动具有重要的科学意义。基于WRF中尺度气象研究模式,对2015年3月30日-4月2日的降水过程进行模拟分析,江淮气旋由于倒槽锋生产生,江苏地区和...在雨中舰载激光武器和激光雷达的工作效能受到制约。因此,研究激光在降水中的衰减特性对军事行动具有重要的科学意义。基于WRF中尺度气象研究模式,对2015年3月30日-4月2日的降水过程进行模拟分析,江淮气旋由于倒槽锋生产生,江苏地区和朝鲜半岛、日本等的降水过程就是高空西风急流与低空急流耦合的结果,与此同时还有700 h Pa切变线的配合。在气旋降水条件下,传输性能较好的10.6μm远红外波仍然受到衰减,在小雨的情况下(降雨率为0.25mm/h)探测距离可损失10%;在中雨的情况下(降雨率为2.7 mm/h)探测距离为正常情况下的70%;而在大雨情况下(降雨率为6 mm/h)探测距离仅为正常情况下的50%。展开更多
基金jointly supported by the National Basic Research Program of China [973 Program,grant number2015CB954102]the National Natural Science Foundation of China [grant number 41475043]
文摘The Yangtze–Huai River Basin(YHRB)always suffers from anomalously heavy rainfall during the warm season,and has been well explored as a whole area during the past several decades.In this study,the YHRB is divided into two core regions-the northern YHRB(nYHRB)and southern YHRB(sYHRB)-based on 29-year(1979–2007)June–July–August(JJA)temporally averaged daily rainfall rates and the standard deviation of rainfall.A spectral analysis of JJA daily rainfall data over these 29 years reveals that a 3–7-day synoptic-timescale high-frequency mode is absolutely dominant over the nYHRB,with 10–20-day and 15–40-day modes playing a secondary role.By contrast,3–7-day and 10–20-day modes are both significant over the sYHRB,with 7–14-day,15–40-day,and 20–60-day modes playing secondary roles.Based on a comparison between bandpass-filtered rainfall anomalies and original rainfall series,a total of 42,1,5,and 3 heavy rainfall events(daily rainfall amounts in the top 5%of rainy days)are detected over the nYHRB,corresponding to 3–7-day,7–14-day,10–20-day,and 15–40-day variation disturbances.Meanwhile,a total of 28,8,12,and 6 heavy rainfall events are detected over the sYHRB,corresponding to 3–7-day,7–14-day,10–20-day,and 20–60-day variation disturbances.The results have important implications for understanding the duration of summer heavy rainfall events over both regions.
文摘在雨中舰载激光武器和激光雷达的工作效能受到制约。因此,研究激光在降水中的衰减特性对军事行动具有重要的科学意义。基于WRF中尺度气象研究模式,对2015年3月30日-4月2日的降水过程进行模拟分析,江淮气旋由于倒槽锋生产生,江苏地区和朝鲜半岛、日本等的降水过程就是高空西风急流与低空急流耦合的结果,与此同时还有700 h Pa切变线的配合。在气旋降水条件下,传输性能较好的10.6μm远红外波仍然受到衰减,在小雨的情况下(降雨率为0.25mm/h)探测距离可损失10%;在中雨的情况下(降雨率为2.7 mm/h)探测距离为正常情况下的70%;而在大雨情况下(降雨率为6 mm/h)探测距离仅为正常情况下的50%。
