西北太平洋2001-2014年热带气旋结构变化的环境垂直风切变和水汽场统计

利用Best Track资料、TRMM卫星资料和NCEP再分析资料中2001—2014年西北太平洋海域385个热带气旋(TC)的4967个观测记录, 将TC结构变化分成9类, 并分析 TC结构变化对垂直风切变和水汽场的响应。结果表明, 西北太平洋强度增大的TC主要伴随东风切变, 强度减小的TC主要伴随西风切变。在较强的垂直风切变(v > 5 m/s)作用下, TC的结构变化没有明显的水汽异常; 而在较弱的垂直风切变(v ≤ 5 m/s)作用下, “增强增大” (“缩小减弱”)的TC伴随着正(负)水汽异常。

Statistics of Environmental Vertical Wind Shear and Water Vapor Field on the Change of Tropical Cyclone Structure in Northwest Pacific Ocean from 2001 to 2014

A total of 4967 observations of 385 tropical cyclones (TCs) in the Northwest Pacific Ocean from 2001 to 2014 from the Best Track data, the Tropical Rainfall Measuring Mission (TRMM) satellite data and the National Centers for Environmental Prediction (NCEP) reanalysis data were classified to compare and analyze the response of environmental vertical wind shear and water vapor field on TC structural change. The results show that intensify TCs are mainly accompanied by east wind shear, and weaken TCs are mainly accompanied by west wind shear. Under the strong vertical wind shear (v > 5 m/s), there is no obvious water vapor anomaly on TC structural change. Under the weak vertical wind shear (v ≤ 5 m/s), the intensify (weaken) TC is accompanied by positive (negative) water vapor anomaly.