Publication Date:
2023-09-06
Description:
The lower limb of the Atlantic meridional overturning circulation (AMOC) is the net equatorward flow of dense waters that have been transformed due to the cooling and freshening of the lighter, poleward-flowing, upper limb waters. In the subpolar North Atlantic (SPNA), upper limb variability is primarily set by the North Atlantic Current, whereas lower limb variability is less well understood, particularly at subseasonal timescales. Using observations from a SPNA mooring array between Greenland and Scotland, we show that variability of the AMOC’s lower limb is connected to poleward flow in the interior Irminger Sea. We identify this flow as the northward branch of the Irminger Gyre (IG), accounting for over 55% of the AMOC’s lower limb variability on monthly timescales. Increasing thickness of intermediate water within the Irminger Sea coincides with decreasing IG recirculation on interannual timescales. Wind stress curl fluctuations over the Labrador Sea, associated with the North Atlantic Oscillation, drive the IG on monthly timescales.
Language:
English
Type:
info:eu-repo/semantics/conferenceObject
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