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Center for Nonlinear Studies |
The meridional overturning circulation in the North Atlantic Ocean is peculiarly strong and plays a large role in North Atlantic regional climate. There are indications that this circulation may weaken significantly in the coming decades in response to anticipated changes in the freshwater cycle from global warming. The importance of fresh, cold outflows from the Arctic in this weakening seems especially important. This talk will discuss these issues and present some recent results on estimating these Arctic outflows east of Greenland. There appear to be multiple dynamical processes by which the outflows enter the North Atlantic Ocean. The importance of O(1km)-scale mechanisms appears to have a disproportionately large impact on the basin-scale flow. There are also some aspects of this small-scale circulation that are surprisingly predictable. In particular, we find that 2-4 day variations in the Denmark Strait Overflow transport can be inferred from knowledge of sea-surface height at Denmark Strait. Experiments with eddy-resolving data assimilation also show skill in tracking the phase and amplitude of these oscillations.
Host: Greg Eyink, CNLS