Asymmetrical response of summer rainfall in East Asia to CO2 forcing

• 作者: Se-Yong Song Sang-Wook Yeh Soon-Il An Jong-Seong Kug Seung-Ki Min Seok-Woo Son Jongsoo Shin
• 来源期刊: 科学通报（英文版）
• 年，卷（期）: 2022,（2）
• 所属期刊栏目: ARTICLES
• 页码范围: 213-222
• 页数: 10页
• 语种: 英文

摘要

Understanding the regional hydrological response to varying CO2 concentration is critical for cost-benefit analysis of mitigation and adaptation polices in the near future.To characterize summer monsoon rainfall change in East Asia in a changing CO2 pathway,we used the Community Earth System Model (CESM) with 28 ensemble members in which the CO2 concentration increases at a rate of 1％ per year until its quadru-pling peak,i.e.,1468 ppm (ramp-up period),followed by a decrease of 1％ per year until the present-day climate conditions,i.e.,367 ppm (ramp-down period).Although the CO2 concentration change is sym-metric in time,the amount of summer rainfall anomaly in East Asia is increased 42％ during a ramp-down period than that during a ramp-up period when the two periods of the same CO2 concentration are compared.This asymmetrical rainfall response is mainly due to an enhanced El Ni(n)o-like warming pattern as well as its associated increase in the sea surface temperature in the western North Pacific dur-ing a ramp-down period.These sea surface temperature patterns enhance the atmospheric teleconnec-tions and the local meridional circulations around East Asia,resulting in more rainfall over East Asia during a ramp-down period.This result implies that the removal of CO2 does not guarantee the return of regional rainfall to the previous climate state with the same CO2 concentration.