资源环境科技发展态势分析平台

The projected widening and weakening of the Hadley circulation hold large societal impacts at low and subtropical latitudes. Previous studies suggested that ocean heat transport might play a central role in the circulation’s changes. Here, using ensembles of model integrations, we quantify the role of ocean heat transport in the evolution of the Hadley cell over the 20th and 21st centuries. We find that by the end of the current century ocean heat transport reduces the widening of the circulation by ∼ 35% (0.42°) and its weakening by ∼ 60% (1.3 × 10¹⁰ kgs⁻¹). As a result, ocean heat transport delays the emergence from internal variability of the widening by 30 years and of the weakening by 20 years. Lastly, while oceanic heat uptake accounts for most of the reduced widening, and thus merely delays it by reducing surface warming, horizontal heat transport and net heat uptake have comparable impacts to reduce the weakening of the circulation.