A sea change in our view of overturning in the subpolar North Atlantic

To provide an observational basis for the Intergovernmental Panel on Climate Change projections of a slowing Atlantic meridional overturning circulation (MOC) in the 21st century, the Overturning in the Subpolar North Atlantic Program (OSNAP) observing system was launched in the summer of 2014. The first 21-month record reveals a highly variable overturning circulation responsible for the majority of the heat and freshwater transport across the OSNAP line. In a departure from the prevailing view that changes in deep water formation in the Labrador Sea dominate MOC variability, these results suggest that the conversion of warm, salty, shallow Atlantic waters into colder, fresher, deep waters that move southward in the Irminger and Iceland basins is largely responsible for overturning and its variability in the subpolar basin.

为了为政府间的大西洋集会推翻循环速度放缓的气候变化预测（MOC）提供观察基础，在2014年夏季推出了高度可变的循环循环，该循环的循环范围是21世纪21世纪的大西洋子午线倾斜循环（MOC），在北大西洋北部大西洋计划（OSNAP）观察系统中的倾覆是在2014年夏季发起的。 线。在与普遍的观点不同的是，拉布拉多海中的深水形成变化占主导地位的MOC可变性，这些结果表明，温暖，咸，浅的大西洋水域转化为在Irminger和Iceland盆地向南移动的更冷，更新鲜的深水，在很大程度上负责在下层基础上驱动其可变性。