Category 5 typhoon Megi was the most intense typhoon in 2010 of the world. It lingered in the South China Sea （SCS） for 5 d and caused a significant phytoplankton bloom detected by the satellite image. In this study...Category 5 typhoon Megi was the most intense typhoon in 2010 of the world. It lingered in the South China Sea （SCS） for 5 d and caused a significant phytoplankton bloom detected by the satellite image. In this study, the authors investigated the ocean biological and physical responses to typhoon Megi by using chlorophyll-a （chl-a） concentration, sea surface temperature （SST）, sea surface height anomaly （SSHA）, sea surface wind measurements derived from different satellites and in situ data. The chl-a concentration （〉3 mg/m3） increased thirty times in the SCS after the typhoon passage in comparison with the mean level of October averaged from 2002 to 2009. With the relationship of wind stress curl and upwelling, the authors found that the speed of upwelling was over ten times during typhoon than pre-typhoon period. Moreover, the mixed layer deepened about 20 m. These reveal that the enhancement of chl-a concentration was triggered by strong vertical mixing and upwelling. Along the track of typhoon, the maximum sea surface cooling （6-8~C） took place in the SCS where the moving speed of typhoon was only 1.4-2.8 m/s and the mixed layer depth was about 20 m in pre-typhoon period. However, the SST drop at the east of the Philippines is only 1-2~C where the translation speed of typhoon was 5.5-6.9 m/s and the mixed layer depth was about 40 m in pre-typhoon period. So the extent of the SST drop was probably due to the moving speed of typhoon and the depth of the mixed layer. In addition, the region with the largest decline of the sea surface height anomaly can indicate the location where the maximum cooling occurs.展开更多
This paper reports the post-disaster results due to Typhoon Megi. The survey was conducted by a joint survey team of Shanghai Typhoon Institute in 14 December 2016, with the support of Wenzhou Meteorological Bureau an...This paper reports the post-disaster results due to Typhoon Megi. The survey was conducted by a joint survey team of Shanghai Typhoon Institute in 14 December 2016, with the support of Wenzhou Meteorological Bureau and some meteorological departments in disaster areas. The survey results show that Typhoon Megi brought torrential rain and heavy rainstorm to the southern of Wenzhou City. The precipitation characters of Typhoon Megi are strong intensity, high accumulation, long duration and broken historical record. Typhoon winds affected wide,with large peripheral wind. According to the needs of defense and emergency rescue of Typhoon Megi,Wenzhou meteorological departments made every effort, including closely monitor, strengthening consultation, roll forecast, timely warning, active reporting, and targeted service. In order to provide scientific reference for government decision, the service of weather protection and disaster relief were done well. The results of typhoon forecast shows as follows.(1) The track, landing location and time of typhoon forecast were basically consistent with the actual situation.(2) The wind forecast was close to the actual.(3) The forecasted area precipitation was slightly lower, and the extreme value of process precipitation was too low. While the prediction of Dongtou Island Station was too high, this investigation shows that we are still insufficient in forecasting precipitation grades of typhoons breaking historical records, especially for precipitation quantification and meticulous prediction. In this case, more attention should be paid as below. 1) Effect of topography on precipitation enhancement. 2) Summary of similar cases. 3) Improve the defense ability and residents' awareness of risk. 4)Combine modem methods of early warning information with traditional methods. 5) Quantitative, fixed-pointed and precision forecast. 6) Rapid access of referent information to forecasters, 7) Modern monitoring technology(3 S, unmanned aerial vehicle) should be used for disaster investigation, monitor and hidden trouble detection.8) Carry out the renovation of the engineering construction design standards, impact assessment and structure of buildings.展开更多
利用欧洲中期天气预报中心(ECMWF) ERA Interim全球再分析资料(1.5°×1.5°)分析了1013号超强台风"鲇鱼"存在期间其东侧东风波的演变、结构以及对台风"鲇鱼"北翘路径的影响。结果显示:在"鲇鱼&qu...利用欧洲中期天气预报中心(ECMWF) ERA Interim全球再分析资料(1.5°×1.5°)分析了1013号超强台风"鲇鱼"存在期间其东侧东风波的演变、结构以及对台风"鲇鱼"北翘路径的影响。结果显示:在"鲇鱼"存在期间,副热带高压南部、台风"鲇鱼"以东存在明显的中高空东风波。在"鲇鱼"以东和180°以西存在明显的两脊一槽结构。从250 hPa的位势高度场中心位置来看,其路径经历了西南偏西向西北偏西方向的转变,并最终同"鲇鱼"的高空环流合并。由于东风波槽西移,位于"鲇鱼"南侧的低压环流上空东风迅速增强,垂直切变加大,从而使得此低压环流减弱、消失。低压环流的消失使得"鲇鱼"南侧南风迅速加强。东风波槽的减弱、北抬,其两侧的高压脊区加强、合并。在"鲇鱼"西北侧西风槽发展南落的共同影响下,台风"鲇鱼"路径发生北翘。展开更多
基金The National Basic Research Program "973" Program of China under contract No.2009CB421202the National Natural Science Foundation of China under contract Nos 40976110 and 40706061+1 种基金the Public Science and Technology Research Funds Projects of Ocean under contract No.200905012the Zhejiang Provincial Natural Science Foundation of China under contract No.Y5090381
文摘Category 5 typhoon Megi was the most intense typhoon in 2010 of the world. It lingered in the South China Sea （SCS） for 5 d and caused a significant phytoplankton bloom detected by the satellite image. In this study, the authors investigated the ocean biological and physical responses to typhoon Megi by using chlorophyll-a （chl-a） concentration, sea surface temperature （SST）, sea surface height anomaly （SSHA）, sea surface wind measurements derived from different satellites and in situ data. The chl-a concentration （〉3 mg/m3） increased thirty times in the SCS after the typhoon passage in comparison with the mean level of October averaged from 2002 to 2009. With the relationship of wind stress curl and upwelling, the authors found that the speed of upwelling was over ten times during typhoon than pre-typhoon period. Moreover, the mixed layer deepened about 20 m. These reveal that the enhancement of chl-a concentration was triggered by strong vertical mixing and upwelling. Along the track of typhoon, the maximum sea surface cooling （6-8~C） took place in the SCS where the moving speed of typhoon was only 1.4-2.8 m/s and the mixed layer depth was about 20 m in pre-typhoon period. However, the SST drop at the east of the Philippines is only 1-2~C where the translation speed of typhoon was 5.5-6.9 m/s and the mixed layer depth was about 40 m in pre-typhoon period. So the extent of the SST drop was probably due to the moving speed of typhoon and the depth of the mixed layer. In addition, the region with the largest decline of the sea surface height anomaly can indicate the location where the maximum cooling occurs.
文摘This paper reports the post-disaster results due to Typhoon Megi. The survey was conducted by a joint survey team of Shanghai Typhoon Institute in 14 December 2016, with the support of Wenzhou Meteorological Bureau and some meteorological departments in disaster areas. The survey results show that Typhoon Megi brought torrential rain and heavy rainstorm to the southern of Wenzhou City. The precipitation characters of Typhoon Megi are strong intensity, high accumulation, long duration and broken historical record. Typhoon winds affected wide,with large peripheral wind. According to the needs of defense and emergency rescue of Typhoon Megi,Wenzhou meteorological departments made every effort, including closely monitor, strengthening consultation, roll forecast, timely warning, active reporting, and targeted service. In order to provide scientific reference for government decision, the service of weather protection and disaster relief were done well. The results of typhoon forecast shows as follows.(1) The track, landing location and time of typhoon forecast were basically consistent with the actual situation.(2) The wind forecast was close to the actual.(3) The forecasted area precipitation was slightly lower, and the extreme value of process precipitation was too low. While the prediction of Dongtou Island Station was too high, this investigation shows that we are still insufficient in forecasting precipitation grades of typhoons breaking historical records, especially for precipitation quantification and meticulous prediction. In this case, more attention should be paid as below. 1) Effect of topography on precipitation enhancement. 2) Summary of similar cases. 3) Improve the defense ability and residents' awareness of risk. 4)Combine modem methods of early warning information with traditional methods. 5) Quantitative, fixed-pointed and precision forecast. 6) Rapid access of referent information to forecasters, 7) Modern monitoring technology(3 S, unmanned aerial vehicle) should be used for disaster investigation, monitor and hidden trouble detection.8) Carry out the renovation of the engineering construction design standards, impact assessment and structure of buildings.
文摘利用欧洲中期天气预报中心(ECMWF) ERA Interim全球再分析资料(1.5°×1.5°)分析了1013号超强台风"鲇鱼"存在期间其东侧东风波的演变、结构以及对台风"鲇鱼"北翘路径的影响。结果显示:在"鲇鱼"存在期间,副热带高压南部、台风"鲇鱼"以东存在明显的中高空东风波。在"鲇鱼"以东和180°以西存在明显的两脊一槽结构。从250 hPa的位势高度场中心位置来看,其路径经历了西南偏西向西北偏西方向的转变,并最终同"鲇鱼"的高空环流合并。由于东风波槽西移,位于"鲇鱼"南侧的低压环流上空东风迅速增强,垂直切变加大,从而使得此低压环流减弱、消失。低压环流的消失使得"鲇鱼"南侧南风迅速加强。东风波槽的减弱、北抬,其两侧的高压脊区加强、合并。在"鲇鱼"西北侧西风槽发展南落的共同影响下,台风"鲇鱼"路径发生北翘。
