研究组综合了代理数据和同位素启动的瞬态冰川消退模拟的结果，并表明在海因里希-斯塔迪尔事件1期间，热带辐合带在热带印度洋东部的南移，加强了热带印度洋上空的沃克环流，引发了横跨盆地的东西向降水偶极子。这种偶极子逆转了由于冰川海平面较低而暴露的Sunda和Sahul大陆架导致的纬向降水异常。研究阐明了大气-海洋环流的纬向模式是如何放大或逆转全球气候异常的，还突出了它们对未来气候变化的重要性。
研究人员表示，大西洋经向翻转环流(AMOC)的突变被认为是通过调整热带辐合带(ITCZ)的纬度位置来影响热带水气候的。海因里希-斯塔迪尔事件1 (HS1)涉及近代地质时期最大的大西洋经向翻转环流的减少;然而，在热带印度洋(IO)上空，代理记录显示了以热带东非强烈而广泛的干旱为特征的纬向异常，海洋大陆通常潮湿但环境异质。
附：英文原文
Title: North Atlantic cooling triggered a zonal mode over the Indian Ocean during Heinrich Stadial 1
Author: Xiaojing Du, James M. Russell, Zhengyu Liu, Bette L. Otto-Bliesner, Delia W. Oppo, Mahyar Mohtadi, Chenyu Zhu, Valier V. Galy, Enno Schefu, Yan Yan, Yair Rosenthal, Nathalie Dubois, Jennifer Arbuszewski, Yu Gao
Issue&Volume: 2023-01-04
Abstract: Abrupt changes in the Atlantic meridional overturning circulation (AMOC) are thought to affect tropical hydroclimate through adjustment of the latitudinal position of the intertropical convergence zone (ITCZ). Heinrich Stadial 1 (HS1) involves the largest AMOC reduction in recent geological time; however, over the tropical Indian Ocean (IO), proxy records suggest zonal anomalies featuring intense, widespread drought in tropical East Africa versus generally wet but heterogeneous conditions in the Maritime Continent. Here, we synthesize proxy data and an isotope-enabled transient deglacial simulation and show that the southward ITCZ shift over the eastern IO during HS1 strengthens IO Walker circulation, triggering an east-west precipitation dipole across the basin. This dipole reverses the zonal precipitation anomalies caused by the exposed Sunda and Sahul shelves due to glacial lower sea level. Our study illustrates how zonal modes of atmosphere-ocean circulation can amplify or reverse global climate anomalies, highlighting their importance for future climate change.
DOI: add4909
Source: https://www.science.org/doi/10.1126/sciadv.add4909