Summertime quadruplet heating pattern in the subtropics and the associated atmospheric circulation

Abstract

A quadruple heating pattern is found over each subtropical continent and its adjacent oceans in summer based on data diagnosis. The ocean region to the west is characterized by strong longwave radiative cooling (LO); the western and eastern portions of the continent are dominated by sensible heating (SE) and condensation heating (CO), respectively; and the ocean region to the east is characterized by double dominant heating (D), with LO prevailing CO. These compose a LOSECOD heating quadruplet. Its general feature is heating over the continent and cooling over the oceans. A distinct circulation pattern accompanies this heating pattern: in the upper troposphere, anticyclonic circulation over the continent is accompanied by cyclonic circulations over the oceans on its western and eastern sides; near the surface, cyclonic circulation over the continent is accompanied by anticyclonic circulations over the oceans on both sides. This circulation feature is interpreted as the atmospheric thermal adaptation to the quadruplet heating. It is further demonstrated that the global summer subtropical heating and circulation may be viewed as "mosaics" of such a quadruplet heating and circulation patterns, respectively.