Why is there a tilted cloud vertical structure associated with the northward advance of the East Asian summer monsoon

Abstract

AbstractThe cloud fraction demonstrates an obvious northward‐tilting structure associated with the northward advance of the East Asian summer monsoon. As a follow‐up study, this study explores the physical explanation of the tilted structure based on ERA‐Interim data. The lower convergence center is located on the northern side of the convective center, and the upper divergence center is located on the southern side of the convective center. This specific atmospheric circulation promotes the formation of the tilted cloud vertical structure. Further study shows that the convective instability layer is thinner, and the convective available potential energy is smaller on the northern side of the convective center, favoring the formation of cumulus and altocumulus clouds in the lower troposphere. Condensation from cumulus convection releases latent heat, enhancing convective activity and generating an abundance of deep convective clouds. As the cloud anvils after deep convective clouds collapse, high clouds accumulate in the upper troposphere and are transported to the southern side of the convective center. Therefore, the observed clouds demonstrate a tilted structure. This study can be used to validate cloud vertical structure simulated by climate and weather models.