Persistently Southward of the South Asian High During the Radiative Forcing Stabilization

Abstract

AbstractThe South Asian high (SAH), a large‐scale anticyclone at 100 and 200 hPa on the Asian continent, is driven by South Asian summer monsoon rainfall and heating over the Tibetan Plateau. As one member of the Asian summer monsoon system, the changes of its location and intensity may cause other climate responses. Rainfall‐induced latent heating can affect the SAH change. Previous study revealed that rainfall responses in Indian Ocean are opposite in periods of increased and stabilizing radiative forcing (RF) due to the deep ocean warming over the Southern Ocean. SAH responses during RF increase and stabilization are studied with 13 models from the Extended Representative Concentration Pathway scenario 4.5 (ECP4.5) experiment. At 100 hPa, the SAH intensifies and moves equatorward in increased RF scenario; when RF stabilizing, SAH still shifts southward but with little change in intensity. At 200 hPa, the SAH changes little in both RF increase and stabilization. These opposite responses at different altitudes may be due to the maximum potential temperature at 150–200 hPa, leading to the opposite changes in vertical motion. Results of the linear baroclinic model indicate that (a) during RF increase, diabatic heating () contributes to SAH strengthening, both and the mean advection of stratification change (MASC) lead to SAH southward movement; (b) during RF stabilization, and MASC, contribute to the SAH equatorward displacement. Two components of , the latent heating and residual heating, are canceled out and lead to little change in SAH intensity.