Sun Yong, Ramstein Gilles, Fedorov Alexey V, Ding Lin, Liu Bo
State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources (TPESER), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China.
Laboratoire des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette 91191, France.
Natl Sci Rev. 2024 Oct 22;12(1):nwae375. doi: 10.1093/nsr/nwae375. eCollection 2025 Jan.
The weakening and poleward expansion of the Hadley circulation (HC) are considered robust responses of atmospheric meridional circulation to anthropogenic warming. Climate impacts arising from these changes enhance drought conditions and reduce food production in the affected regions. Therefore, understanding the mechanisms of HC changes is critical to anticipating the resultant climate risks. First, we demonstrate that robust future HC changes in boreal winter, and the uncertainty in their future projections, are both largely related to sea surface temperature (SST) warming. Next, we investigate the impact of anthropogenic regional ocean warming on the future HC. Accordingly, we conduct a large ensemble of individual ocean basin perturbation experiments at 1.5°C, 2°C, and 3°C warming thresholds (as in the Paris Agreement). These experiments highlight (i) the leading role of tropical Indian Ocean warming in HC changes and (ii) inter-model differences in tropical Pacific warming as a source of uncertainty in HC projections.
哈德利环流（HC）的减弱和向极扩张被认为是大气经向环流对人为变暖的有力响应。这些变化所产生的气候影响加剧了受影响地区的干旱状况并减少了粮食产量。因此，了解哈德利环流变化的机制对于预测由此产生的气候风险至关重要。首先，我们证明了北半球冬季未来哈德利环流的强劲变化及其未来预测的不确定性在很大程度上都与海表温度（SST）变暖有关。接下来，我们研究人为区域海洋变暖对未来哈德利环流的影响。因此，我们在1.5°C、2°C和3°C变暖阈值（如《巴黎协定》中所述）下进行了大量单个大洋盆地扰动实验。这些实验突出了（i）热带印度洋变暖在哈德利环流变化中的主导作用，以及（ii）热带太平洋变暖的模式间差异是哈德利环流预测不确定性的一个来源。
