盛夏是我国台风的多发时期,而台风降水是我国降水的重要组成部分,一般认为台风登陆减弱后,其伴随的强风暴雨灾害也会随之减弱,但有时也会出现台风强度减弱而其带来的降水却反而达到大暴雨等级的现象,本文定义这种现象为“弱台风大暴雨...盛夏是我国台风的多发时期,而台风降水是我国降水的重要组成部分,一般认为台风登陆减弱后,其伴随的强风暴雨灾害也会随之减弱,但有时也会出现台风强度减弱而其带来的降水却反而达到大暴雨等级的现象,本文定义这种现象为“弱台风大暴雨”降水事件,即热带气旋2分钟平均近中心最大风速不足32.7 m/s (即未达到台风强度),且单站单日降水量超过100 mm (即达到大暴雨等级)的热带气旋降水事件。对盛夏中国“弱台风大暴雨”事件的年际变化及其可预报性进行了探究,结果表明:前期海表温度场巴伦支海异常增暖导致海冰减少,使得冷空气活动偏南,同时配合前期印度洋偶极子正位相导致的夏季越赤道气流增强,南海地区西南季风携带大量水汽输送北上,使我国降水量增加。而前期拉尼娜型海表温度信号与西太平洋副热带高压的减弱相配合导致影响我国的台风增多,强度偏弱,诱发“弱台风大暴雨”事件。展开更多
In 1998, the annual frequency of typhoon (including tropical storms) genesis created a minimum value — 14, far lower than the minimum of 20 in 1950 over North-West Pacific, while in the Atlantic Ocean, the annual fre...In 1998, the annual frequency of typhoon (including tropical storms) genesis created a minimum value — 14, far lower than the minimum of 20 in 1950 over North-West Pacific, while in the Atlantic Ocean, the annual frequency of hurricanes (including the tropical storm) created a maximum value — 14, far higher than the average number — 9.2. In this paper, an analysis on the relationship between the generation of Typhoon, Hurricane and the Cross-Equatorial Flow was done by using the NCEP/NCAR reanalysis data for 1979 – 1995. It is pointed out that the anomalies of the CEF over the Pacific and Atlantic Ocean is the main cause for the 1998 annual frequency anomalies of Typhoon and Hurricane, respectively.展开更多
Guangdong is a developed province in China, but suffers from frequent typhoon disasters which cause great economic loss. Quantitative regional risk assessment of typhoon disasters is important for disaster prevention ...Guangdong is a developed province in China, but suffers from frequent typhoon disasters which cause great economic loss. Quantitative regional risk assessment of typhoon disasters is important for disaster prevention and mitigation. According to direct economic loss and typhoon intensity information, we established a typhoon disaster loss rate curve using data from 1954 to 2008. Based on GIS spatial module, the economic vulnerabilities of different intensity typhoons were calculated for 98 counties in Guangdong Province. Different intensity typhoon landing frequencies in Guangdong were also calculated, and used to indicate typhoon disaster probability. A risk assessment model was established to assess economic loss risk under different intensity typhoons in Guangdong. The results show that economic loss risk caused by typhoon is more than 10 thousand million CNY; according to typhoon intensity grade, economic risk is up to 10.467, 14.429, 7.753 and 13.591 thousand million CNY for slight, light, medium and severe typhoons, respectively. The Pearl River Delta is the highest risk region, especially Guangzhou, Dongguan, Shenzhen, Zhongshan and Zhuhai. Risk value decreases from Pearl River coastal outfall to the inland in a radial pattern. Inland areas far from coastal counties have lower risk, and the risk value is less than 50 million CNY. When typhoon intensity increases from slight to medium, the risk in western is higher than in eastern parts, but when typhoons become to severe, the risk value in eastern Guangdong part is higher than in the west.展开更多
文摘盛夏是我国台风的多发时期,而台风降水是我国降水的重要组成部分,一般认为台风登陆减弱后,其伴随的强风暴雨灾害也会随之减弱,但有时也会出现台风强度减弱而其带来的降水却反而达到大暴雨等级的现象,本文定义这种现象为“弱台风大暴雨”降水事件,即热带气旋2分钟平均近中心最大风速不足32.7 m/s (即未达到台风强度),且单站单日降水量超过100 mm (即达到大暴雨等级)的热带气旋降水事件。对盛夏中国“弱台风大暴雨”事件的年际变化及其可预报性进行了探究,结果表明:前期海表温度场巴伦支海异常增暖导致海冰减少,使得冷空气活动偏南,同时配合前期印度洋偶极子正位相导致的夏季越赤道气流增强,南海地区西南季风携带大量水汽输送北上,使我国降水量增加。而前期拉尼娜型海表温度信号与西太平洋副热带高压的减弱相配合导致影响我国的台风增多,强度偏弱,诱发“弱台风大暴雨”事件。
基金Research on Short-term Climatic Prediction Systems in China - a core scientific project inthe 9th five-year economic development plan Century-bridging Youth Academic Research Backbones from theChinese Academy of Meteorological Sciences
文摘In 1998, the annual frequency of typhoon (including tropical storms) genesis created a minimum value — 14, far lower than the minimum of 20 in 1950 over North-West Pacific, while in the Atlantic Ocean, the annual frequency of hurricanes (including the tropical storm) created a maximum value — 14, far higher than the average number — 9.2. In this paper, an analysis on the relationship between the generation of Typhoon, Hurricane and the Cross-Equatorial Flow was done by using the NCEP/NCAR reanalysis data for 1979 – 1995. It is pointed out that the anomalies of the CEF over the Pacific and Atlantic Ocean is the main cause for the 1998 annual frequency anomalies of Typhoon and Hurricane, respectively.
基金Key Project of Knowledge Innovation Program of the Chinese Academy of Sciences (GrantNo.KZCX2-YW-Q03-01)National Key Technology R&D Program (Grant No.2008BAK50B06 and 2008BAK50B05)
文摘Guangdong is a developed province in China, but suffers from frequent typhoon disasters which cause great economic loss. Quantitative regional risk assessment of typhoon disasters is important for disaster prevention and mitigation. According to direct economic loss and typhoon intensity information, we established a typhoon disaster loss rate curve using data from 1954 to 2008. Based on GIS spatial module, the economic vulnerabilities of different intensity typhoons were calculated for 98 counties in Guangdong Province. Different intensity typhoon landing frequencies in Guangdong were also calculated, and used to indicate typhoon disaster probability. A risk assessment model was established to assess economic loss risk under different intensity typhoons in Guangdong. The results show that economic loss risk caused by typhoon is more than 10 thousand million CNY; according to typhoon intensity grade, economic risk is up to 10.467, 14.429, 7.753 and 13.591 thousand million CNY for slight, light, medium and severe typhoons, respectively. The Pearl River Delta is the highest risk region, especially Guangzhou, Dongguan, Shenzhen, Zhongshan and Zhuhai. Risk value decreases from Pearl River coastal outfall to the inland in a radial pattern. Inland areas far from coastal counties have lower risk, and the risk value is less than 50 million CNY. When typhoon intensity increases from slight to medium, the risk in western is higher than in eastern parts, but when typhoons become to severe, the risk value in eastern Guangdong part is higher than in the west.
