讲座题目：Energetics Theory as the Crystal Ball for the Projection of Asian Monsoon Rainfall under Global Warming
主讲人：吕健 教授
主持人：刘东艳 研究员
开始时间：2025-03-28 14:00
讲座地址：闵行校区河口海岸大楼A204
主办单位：河口海岸科学研究院
报告人简介：
吕健，中国海洋大学海洋与大气学院筑峰教授。博士毕业于中国海洋大学和Dalhousie大学。曾在普林斯顿的地球流体力实验室和美国国家大气科学中心从事博士后研究。曾就职于乔治梅森大学，COLA和美国西北太平洋国家实验室。曾担任Climate Dynamics编委, 现担任 Journal of Climate, 中国科学和大气科学进展的编委。发表论文170余篇。自2024年10月入职中国海洋大学。主要从事气候与气候变化的大尺度动力学研究。研究方向包括大气环流的动力机制、波流相互作用、海气相互作用，以及从动力系统的角度考察气候系统的强迫相应关系及其在气候工程上的应用。
报告内容：
During the past two decades or so, the energetic perspective has been gaining traction in understanding the response of the tropical rainfall to climate change, bringing the global hydrological response to climate change under the auspice of climate radiative feedbacks. In this talk I will tell a two-part story: I. the response of the South Asian Monsoon (SAM) circulation to global warming; II. Mode-based future projection of the East Asian Monsoon rainfall, with the energetic constraints underpinning the robust aspects of the future climate projections in the two stories. We first show that the uncertain SAM circulation in CMIP6 consists of two robust components that partly offset each other: a weakening component linked to a global thermodynamic constraint and a northward shift component, the latter being interpretable through a regional 2D energetic perspective. We further attribute the robust northward shift of SAM circulation to positive cloud feedback over the Eurasia Continent and heat uptake in the Southern Ocean. A set of climate model simulations supports the finding that SAM rainfall increase is primarily due to the northward shift of circulation driven by extratropical processes. This energetic perspective opens new avenues for predicting monsoon rainfall by connecting circulation changes to radiative forcing, feedbacks, and ocean heat uptake. East Asian Summer Monsoon (EASM) is a complex system involving interplay between the tropical moist dynamics, energetic constraint, jet dynamics, and jet-topography interaction. There is high uncertainty also in the future projection of the EASM. Here, we assess the future changes in the East Asian summer monsoon precipitation by projecting the precipitation from several large ensemble simulations and CMIP6 simulations onto the two leading dynamical modes of internal variability. The result shows a remarkable agreement among the ensembles on the increasing trends and the increasing daily variability in both dynamical modes, with the projection pattern emerging as early as the late 2030s. The increase of the daily variability of the modes heralds more monsoon-related hydrological extremes over some identifiable East Asian regions in the coming decades.
