The Response of a Zonally Symmetric Atmosphere to Subtropical Thermal Forcing: Threshold Behavior

摘要: Abstract We consider the response of a zonally symmetric atmosphere to thermal forcing that is localized in subtropics. Specifically, equilibrium temperature distribution has local subtropical peak and flat elsewhere, including at equator. On basis inviscid steady-state theory, it argued such one two distinct types. Below threshold adopts steady state with no meridional flow. With supercritical forcing, this breaks down strong circulation predicted. The value which absolute vorticity zonal flow (in gradient balance temperatures) vanishes upper boundary. These predictions are tested numerical model; while model viscosity shifts otherwise modifies response, clearly evident behavior.