利用卫星遥感资料分析台风“烟花”(202106)的影响过程

Analysis of influence process of Typhoon In-fa (202106) based on satellite remote sensing data

摘要:

2021年第6号台风“烟花”于7月18日生成，7月30日变性为温带气旋，生命史长达13 d，先后对中国东部14个省市造成影响，其主要特点是移动速度慢、陆上滞留时间长和累积雨量大。基于静止气象卫星、极轨气象卫星和全球降水测量卫星的多通道观测和产品，对“烟花”的影响过程进行分析。结果表明：“烟花”空间尺度较大（最大半径约为350 km），登陆前对流深厚、云系螺旋特征显著，登陆后云系结构遭到破坏、中等对流分布密集但没有组织性；“烟花”在洋面上时液态水和冰态水含量丰富并表现出非对称分布，登陆后液态水和冰态水主要集中在台风前进方向的右侧。基于微波成像仪的降水反演结果显示：降水主要分布在台风外围螺旋雨带位置，且在位置和形态上与实况较吻合；虽然雨量估计值与实况存在一定偏差，但对降水预报，特别是常规资料稀少区域的降水预报仍具有参考意义。

Abstract:

Typhoon In-fa (202106) formed on July 18, 2021, and became an extratropical cyclone on July 30, with a life history of 13 d.It affected 14 provinces and cities in eastern China.Its main characteristics are slow moving speed, long retention time on land and large accumulated rainfall.Based on multi-channel observations and products from geostationary meteorological satellites, polar-orbiting meteorological satellites and global precipitation measurement satellites, this paper analyzes the influence process of Typhoon In-fa.Results show that the spatial scale of Typhoon In-fa is large, with the maximum radius of about 350 km.Before landing, the convection is deep and the spiral characteristics of the cloud system are significant.After landing, the cloud system structure is destroyed and the medium convection is densely distributed but unorganized.When Typhoon In-fa is on the ocean surface, the liquid water and ice water are rich and show asymmetric distribution.After landing, the liquid and ice water are mainly concentrated on the right side of forward direction of the typhoon.Based on microwave imager, the retrieved precipitation rate show that the precipitation mainly locates in the spiral rain belt around the typhoon, and the position and area are in good agreement with the observations.Although there is a certain deviation between the estimated precipitation and the observed precipitation, it is still useful for precipitation forecasting, especially in regions where the conventional data are scarce.