研究人员通过进行大集合实验，发现二氧化碳浓度系统增加，然后降低到现在的水平，研究人员称，当二氧化碳浓度降低时，变暖气候中向极地移动的哈得来环流边缘不会返回到现在的状态。当南半球哈得来环流边缘保持向其当前的状态的极处移动时，北半球哈得来环流边缘终止于其当前状态的更赤道处。
这种半球不对称的哈得来环流边缘的变化与副热带大气中垂直风切变的变化密度相关，这是由于海洋对二氧化碳去除的响应需要较长的调整时间。研究表明，二氧化碳的去除可能不保证与哈得来环流变化相关的亚热带干旱的恢复。
据介绍，在气候变暖的情况下，哈得来环流(HC)边缘向极地移动，这有助于易干旱的亚热带地区的扩张，这一现象已被广泛记录。这里解决的问题是这种转变是否随着二氧化碳的去除而可逆。
附：英文原文
Title: Hemispherically asymmetric Hadley cell response to CO2 removal
Author: Seo-Yeon Kim, Yeong-Ju Choi, Seok-Woo Son, Kevin M. Grise, Paul W. Staten, Soon-Il An, Sang-Wook Yeh, Jong-Seong Kug, Seung-Ki Min, Jongsoo Shin
Issue&Volume: 2023-07-26
Abstract: A poleward shift of the Hadley cell (HC) edge in a warming climate, which contributes to the expansion of drought-prone subtropical regions, has been widely documented. The question addressed here is whether this shift is reversible with CO2 removal. By conducting large-ensemble experiments where CO2 concentrations are systematically increased and then decreased to the present-day level, we show that the poleward-shifted HC edge in a warming climate does not return to its present-day state when CO2 concentrations are reduced. While the Southern Hemisphere HC edge remains poleward of its present-day state, the Northern Hemisphere HC edge ends up farther equatorward of its present-day state. Such hemispherically asymmetric HC edge changes are closely associated with the changes in vertical wind shear in the subtropical atmosphere, which result from the long adjustment time of the ocean response to CO2 removal. Our findings suggest that CO2 removal may not guarantee the recovery of the subtropical dryness associated with the HC changes.
DOI: adg1801
Source: https://www.science.org/doi/full/10.1126/sciadv.adg1801