Rubbelke Claire B, Bhattacharya Tripti, Farnsworth Alexander, Valdes Paul, McClymont Erin L, Ford Heather
Department of Earth and Environmental Sciences, Syracuse University, Syracuse, NY, USA.
School of Geographical Sciences, University of Bristol, Bristol, UK.
Nat Commun. 2025 Apr 12;16(1):3501. doi: 10.1038/s41467-025-58792-5.
Southern African (SA) hydroclimate is largely shaped by the interactions of atmospheric circulations, e.g., Hadley Circulation, and oceanic elements, like the Benguela Upwelling System (BUS), Agulhas System, and Antarctic Circumpolar frontal system. Large-scale changes to the Meridional Temperature Gradient (MTG) influence both the atmospheric and oceanic components of the hydroclimate system, and thus impact hydroclimate over SA. We present a leaf wax hydroclimate record from ODP 1084, in the BUS, which reveals that changes in the isotopic signature of precipitation over SA coincide with a strengthening of the MTG across the Mid-Pleistocene Transition (MPT). We use HadCM3 simulations to demonstrate the sensitivity of winter rainfall to shifts in the MTG during the MPT. Given the ongoing impacts of climate change on water resources in SA, awareness of the relationship between rainfall and shifts in Hadley Circulation could provide insight into past water availability and aid regional adaptation efforts.
南部非洲（SA）的水文气候很大程度上是由大气环流（如哈德利环流）与海洋要素（如本格拉上升流系统（BUS）、厄加勒斯系统和南极绕极锋面系统）之间的相互作用塑造的。经向温度梯度（MTG）的大规模变化影响着水文气候系统的大气和海洋成分，进而影响南部非洲的水文气候。我们展示了来自BUS中ODP 1084的叶蜡水文气候记录，该记录显示，在中更新世过渡（MPT）期间，南部非洲降水同位素特征的变化与MTG的增强相吻合。我们使用HadCM3模拟来证明MPT期间冬季降雨对MTG变化的敏感性。鉴于气候变化对南部非洲水资源的持续影响，了解降雨与哈德利环流变化之间的关系有助于深入了解过去的水资源状况，并助力区域适应工作。
