**An EOF Analysis and Modeling Study of the Multi-Typhoons Movement over the West Northern Pacific and the South China Sea

A fifty-year (1949-1998) dataset of multi-typhoon tracks were evaluated to determine the general characteristics of the relative motion between the corresponding typhoons over the South China Sea and the northwest Pacific. The interaction of binary and/or triplet typhoons is divided into several classes according to the relative distance and rotation, and position of typhoon centers. Furthermore, the influences of steering flow and terrain on the interaction are also explored through a conceptual model and case analyses.

Further evidences show that the relative motion of multi-typhoons doesn't coincide with Fujiwhara effect which fulfilled in a laboratory experiments. The interaction between typhoons in reality is dependent upon the steering flow, and the effect of the topography should not be neglected. Except for that, the result also exhibits the interaction of binary typhoon has much impacts on the typhoon track.