The Mozambique Channel is a conduit of trade wind-driven throughflow that is a key component of the Agulhas Current and Agulhas leakage, a flux of warm and salty water from the tropical Indo-Pacific to the Atlantic Ocean. Agulhas leakage is thought to modulate Atlantic meridional overturning circulation variability. Previous studies from the Cape Basin suggest that enhanced Agulhas leakage played an important role in accelerating glacial terminations. The southern African monsoon response to abrupt climate changes associated with meltwater-induced reorganizations of the North Atlantic meridional overturning circulation, and its impact on the Mozambique Channel throughflow and, by extension, on the Agulhas leakage is not well understood. Here we present a high-resolution 26,000 year-long hydroclimate record of northern Madagascar, a core region of the southern hemisphere monsoon domain, and a mixed layer temperature reconstruction using sediment cores collected from the runoff-influenced eastern Mozambique Channel. The record indicates precipitation increases centered at 11.7-12.5 thousand years before present (kyr BP), 14.5-19 kyr BP, 23-24 kyr BP, 25-26 kyr BP. Considering age model uncertainties, this is the first strong evidence for southern African monsoon strengthening in response to meltwater-induced northern high latitude climate instabilities during the Younger Dryas (YD), Heinrich Stadial 1 (HS1), HS2 and the HS-like event prior to HS2, in agreement with the results of transient climate simulations. Furthermore, our study shows a reversal of the mixed layer temperature gradient between the western and eastern Mozambique Channel during Heinrich event 1 (HE1). We posit that the gradient reversal indicates a weakening of the trade wind-driven South Equatorial Current and Mozambique Channel throughflow that likely weakened the Agulhas leakage, potentially creating a feedback that may have contributed to the sustained weakening of the AMOC during HE1 by reducing the amount of heat and salt leakage into the Atlantic.

莫桑比克海峡是信风驱动的通流管道，是厄加勒斯海流和厄加勒斯渗漏的关键组成部分，厄加勒斯渗漏是从热带印度洋-太平洋到大西洋的暖咸水通量。Agulhas 泄漏被认为调节大西洋经向翻转环流变化。先前来自开普盆地的研究表明，增强的 Agulhas 渗漏在加速冰川终止方面发挥了重要作用。南部非洲季风对与融水引起的北大西洋经向翻转环流重组相关的突然气候变化的响应，及其对莫桑比克海峡通流的影响，进而对厄加勒斯渗漏的影响尚不清楚。在这里，我们展示了马达加斯加北部长达 26,000 年的高分辨率水文气候记录，南半球季风域的核心区域，以及使用从受径流影响的莫桑比克东部海峡收集的沉积物核心重建混合层温度。记录表明降水增加集中在现在之前的 11.7-12.5 万年（kyr BP）、14.5-19 kyr BP、23-24 kyr BP、25-26 kyr BP。考虑到年龄模型的不确定性，这是南部非洲季风加强的第一个有力证据，以应对新仙女木 (YD)、海因里希体育场 1 (HS1)、HS2 和 HS 类似事件期间融水引起的北部高纬度气候不稳定性。 HS2，与瞬态气候模拟的结果一致。此外，我们的研究表明，在海因里希事件 1 (HE1) 期间，莫桑比克海峡西部和东部之间的混合层温度梯度发生了逆转。