Dynamic effect of ice sheet topography on east Asian summer monsoon during the last deglaciation

Yu Gao, PhD candidate, Peking University (China)
Bryan Mark, faculty mentor

Background

• Hometown: Yangzhou, China
• Degrees received: Bachelor of Science in atmospheric sciences, Nanjing University, China

What is the issue or problem addresses in your research?

The effect of deglacial ice sheet retreat on East Asian Summer Monsoon during the last 19,000 years is studied using CCSM3 (a fully coupled climate model), with the focus on the orographic effect. It is found that receding ice sheets result in a weakened east Asian summer monsoon, with the reduced ice sheet thickness playing a major role.

What methodology did you use in your research?

I used climate model simulations in my research. The model I used is Community Climate System Model version 3 (CCSM3) provide by NCAR. I did further analyses based on a transient simulation of the global climate of the last 19,000 years forced only by the deglacial evolution of the ice sheets (TRACE-ICE). I also did sensitivity experiments in a hierarchy of models to find out the physical mechanisms on how ice sheets influence Asian monsoon.

What are the purpose/rationale and implications of your research?

Understanding the past significant changes of the East Asia Summer Monsoon is critical for improving the projections of future climate over East Asia. When studying the impact of ice sheet on global monsoon systems, the simple thermodynamic view from observational studies is challenged by recent modeling studies. The objective of this study is a thorough understanding of the mechanism of the ice sheet impact on East Asian Summer Monsoon in CCSM3.