Large-Scale Circulation Patterns Favorable to Tropical Cyclogenesis over the Western North Pacific and Associated Barotropic Energy Conversions

摘要

A key in forecasting the formation of tropical cyclones is whether or not the large-scale circulation pattern is favorable to tropical cyclogenesis.Using the National Centers for Environmental Prediction-Department of Energy (NCEP-DOE) reanalysis and the Joint Typhoon Warning Center (JTWC) best track data for the period 1991-2010,the present study classifies five large-scale circulation patterns in association with the tropical cyclone (TC) formation over the western North Pacific (WNP):the monsoon shear (MS),the monsoon confluence (MC),the reverse-oriented monsoon trough (RMT),the monsoon gyre (MG),and the trade wind easterlies (TE).