An objective method for discriminating the process of extratropical transition （ET） in tropical cyclones is introduced. With this method, the gridpoint output data of NWP are used to calculate three parameters： sto...An objective method for discriminating the process of extratropical transition （ET） in tropical cyclones is introduced. With this method, the gridpoint output data of NWP are used to calculate three parameters： storm-relative thickness symmetry （B）, low-level （-VL^L ） and upper-level thermal wind （-VT^U ）. This objective method is easy to calculate and convenient for operational use. To verify the method, this paper uses the NCEP reanalysis data to identify the evolution of ET for ＂Haima＂, a tropical storm （0421） that affected the eastern part of China in 2004. The result shows that the three parameters defined with the objective method are good indicators of the ET process.展开更多
基金Integrated Operational Services/Pre-warning System for Tropical Cyclones from China Meteorological AdministrationTyphoon Research Foundation for Shanghai Typhoon Institute
文摘An objective method for discriminating the process of extratropical transition （ET） in tropical cyclones is introduced. With this method, the gridpoint output data of NWP are used to calculate three parameters： storm-relative thickness symmetry （B）, low-level （-VL^L ） and upper-level thermal wind （-VT^U ）. This objective method is easy to calculate and convenient for operational use. To verify the method, this paper uses the NCEP reanalysis data to identify the evolution of ET for ＂Haima＂, a tropical storm （0421） that affected the eastern part of China in 2004. The result shows that the three parameters defined with the objective method are good indicators of the ET process.
