As the global ocean gradually warms, the North Atlantic is undergoing some remarkable hydrographic changes. These include a contrast between upper cooling (0-1000m) and intermediate warming (1000-2000m) ,which further demonstrates the strong imprint of ocean dynamics on the local temperature field.
I will present a full-depth picture of the global temperature trend derived from Argo and repeat hydrography, detailing its vertical and basin-scale structure. This will provide context for a mechanistic analysis of the North Atlantic variability. I will present on-going work on the successive states of the multi-decadal signal, from its formation and northward spreading in the upper layer, its light-to-dense transformation at high latitudes, and its slow deep return towards the subtropics.