Results of Numerical Modeling of the Origin of Cyclones and Anticyclones in the Vicinity of the Intertropical Convergence Zone

Abstract

A review of simulation results, devoted to time-dependent modeling of the initial stage of the formation of large-scale vortices in the troposphere in the vicinity of the intertropical convergence zone, is presented. The simulation results were obtained not long ago with the help of the mathematical model of the neutral wind system of the lower atmosphere, developed earlier in the Polar Geophysical Institute. The utilized mathematical model produces three-dimensional distributions of the atmospheric parameters in the height range from 0 to 15 km over a limited region of the Earth's surface. Simulation results were obtained for the case when the limited three-dimensional simulation domain, situated at low latitudes, is intersected by an intertropical convergence zone in the west-east direction. The reviewed simulation results were obtained for various initial configurations of the intertropical convergence zone. Results of numerical modeling have indicated that the origin of convexities in the form of the intertropical convergence zone can lead to the formation of different large-scale vortices in the lower atmosphere, in particular, a tropical cyclone, pair of cyclonic vortices, pair of cyclonic-anticyclonic vortexes, and triplet of cyclonic vortices. The simulation results, obtained earlier and presented individually in various editions, are reviewed and summarized in the present paper. A physical mechanism, responsible for the formation of the simulated large-scale vortices in the vicinity of the intertropical convergence zone, is discussed.