New Climate Diagnostic Method of Activity of Typhoons over the Northwestern Pacific Ocean

A new conception, called the Most Direct Impact Area (MDIA) of typhoons, is put forward in this paper. After the computational method is explained in detail, the databank of 1955 typhoons of China Meteorological Administration (CMA) have been calculated on the Linux operational platform with a Fortran compiler in a computer. The results via calculating the geographic distribution of the MDIA of typhoons show that the characteristic of typhoon activity in a year can be easily identified in quantity. A most interesting feature has been found that typhoon activity is abnormally active over the ocean to the south of Japan in three typical El Niño years.