盛夏中国弱台风大暴雨事件的可预报性
2020-02-2597次
Title:盛夏中国弱台风大暴雨事件的可预报性
Journal:气候变化研究快报，8（4）：365-372
Authors:张希帆，黄菲*，许士斌
Abstract: Typhoon occurs the most frequently in midsummer over China, and typhoon precipitation is an important part of precipitation in China. It is generally believed that after landing typhoon weakened, the accompanying strong storms and rainfalls will also be weakened. However, sometimes heavy rainstorm appears while the typhoon intensity weakens. This paper defines the “weak typhoon heavy rainfall” event, that is, the tropical cyclone does not reach the typhoon-class intensity (averaged wind speed of the tropical cyclone in 2 minutes is less than 32.7 m/s), and daily precipitation at each station exceeds 100 mm (the heavy rainstorm level). And by exploring the predictability and interannual variation of WTHRE, the results show that the abnormal warmth of the Barents Sea in the early sea temperature field caused the sea ice to decrease, which made the cold air activity southward, and cooperated with the positive phase of the previous IOD, which leads the cross-equatorial airflow enhanced in summer and a large amount of vapor transport northward carried with the South summer monsoon, which increases the precipitation in China. The combination of the La Niña-SST signal in the background field of the PDO cold phase and the weakening of the West Pacific subtropical high caused the increase of typhoon affecting China with weak intensity, which induced the WTHRE.