气候变化领域集成服务门户

The spiral signatures of infrared satellite images of the tropical cyclone Phanfone observed in the Northwest Pacific in August 2002 are analyzed using the hyperbolic-logarithmic model of a streamline in the Rankine vortex. Maximum wind speed V-max and some other physical characteristics of the cyclone are estimated by identifying hyperbolic-logarithmic spirals (RLS) which fit into the geometric boundaries of the signatures. The comparison of temporal variations in V-max with the data of meteorological services of the USA (JTWC) and Japan (RSMC) revealed satisfactory agreement of the time course of tropical cyclone intensity from the HLS estimates and JTWC data. The absolute estimates of intensity were within an interval between the corresponding JTWC and RSMC data. It seems that if the presented approach is enhanced, the HLS estimation may be a useful contribution to the empirical methods of tropical cyclone intensity determination by remote sensing means.