Varying Sensitivity of East Asia Summer Monsoon Circulation to Temperature Change Since Last Glacial Maximum

Abstract

Abstract Proxy records of the East Asia summer monsoon (EASM) and temperature reveal an in‐phase relationship of the two since the Last Glacial Maximum (LGM), which is consistent with their expected physical relationship; but the response amplitude of EASM to temperature variation seemed larger over the Holocene than over the last deglaciation. Using a state‐of‐the‐art transient climate simulation, we confirm this proxy‐inferred phenomenon, and estimate the “sensitivity of EASM circulation to summer temperature over adjacent region” (defined as SMT here) is about five times over the Holocene of that over the last deglaciation. This varying SMT attributed to the diverse SMT under the solo forcing of orbital insolation and CO2 (eight times of the former vs. the latter), and their varying confounding effect along time. The results presented here should improve our understanding of the past change of EASM, and help project its variation magnitude under ongoing CO2‐forced global warming.

Keywords

• EASM
• Temperature
• Sensitivity
• CO2
• Insolation
• Seasonality