西北太平洋海面高度异常对热带气旋的响应

采用一种海面高度异常(Sea Level Anomaly,SLA)对热带气旋响应的合成分析方法,即根据热带气旋的路径位置和运动方向对海面高度异常进行插值、旋转和平均,得到不同热带气旋强度下,以热带气旋最佳路径点为原点的海面高度异常场.利用该方法,基于Aviso卫星高度计数据和中国气象局热带气旋最佳路径数据,得到了199...

Responses of Sea Level Anomaly to Tropical Cyclones in Northwest Pacific Ocean

A composing analytical method,which includes interpolation of sea level anomaly(SLA)field centered at the best track of tropical cyclones(TCs)and rotation of SLA field according to the propagation directions of TCs,was used to analyze the response of SLA to TCs.Responses of SLA to TCs in Northwest Pacific Ocean from 1993 to 2018 were analyzed with the composing analytical method based on Aviso altimetry dataset and CMA’s tropical cyclone database.The results show that the TCs have significant impact on the distribution and evolution of SLA.The SLA started to turn to negative 7 days before TCs’arrival.When TCs arrive,the sea level at the center of TCs decreased significantly,and the sea level on the right side of tropical cyclone tracks increased.The sea level decreased to its lowest value in 6—7 days after TCs’arrival,then rise slowly after that.Both the TC strength and translation speed can affect the spatial and temporal variation of sea level.Stronger TCs can result in lower sea levels.The maximum decrease of sea level can reach 10.93 cm for super Typhoon(wind speed greater than 51.0 m/s).Analysis also showed that,the slower the TCs move,the greater the impacts the TCs have on sea level.The maximum decrease in sea level is 19.79 cm when the translation speed of TCs is less than 5 km/h.