A Spontaneously Generated Tropical Atmospheric General Circulation

Abstract

Abstract A series of idealized atmospheric general circulation model (AGCM) experiments are presented. These experiments examine whether and how atmospheric deep moist convection, in the absence of meridional gradients in external forcing, interacts with the large-scale flow, becoming spatially organized and yielding a coherent general circulation. In a control simulation, where the SST and the incident solar flux are prescribed to be independent of latitude, longitude, and time, a well-defined intertropical convergence zone (ITCZ) forms. This result suggests that the interaction between convection and the rotation of the earth causes convection and a corresponding general circulation to organize. The actual latitude that the ITCZ forms at, however, may be parameterization dependent. In this control simulation, the SST is not interactive and cannot respond to the spatial variations of the heat flux into the ocean that result from the organization of the circulation. In order to examine the circulation tha...