Modeling of Long-Periodic Changes in Atmospheric Motions Based on the Coupling of Simple Convective Systems

The interaction of various climatic zones (northern, temperate and southern) as circulation cells of large-scale atmospheric currents is represented in the form of a superposition of six-dimensional systems that describe the motion of stratified fluids in the space of linear velocity and temperature fields. The effect of each of the zones on neighboring zones occurs only through temperature gradients along the meridional direction which are due to sources and sinks of heat (short-wave radiation, downcoming long-wave radiation, outgoing long-wave radiation). The resulting nonlinear system, in which each of the blocks contains vortex and temperature components of the fields, is discretized by an implicit scheme. Long-period nonlinear oscillations are modeled, showing the natural “breath” of the climate of the atmosphere, in which the amplitudes of vortex intensity and temperature differences of various zones change with characteristic times of decades. In this case, the transition between quasi-stationary states of the system can occur over several years. A comparison is made between various numerical methods that show long-term oscillations in convective systems.