The Irminger Gyre as a key driver of the subpolar North Atlantic overturning
The lower limb of the Atlantic meridional overturning circulation (AMOC) is the equatorward flow of dense waters formed through the cooling and freshening of the poleward-flowing upper limb. In the subpolar North Atlantic (SPNA), upper limb variability is primarily set by the North Atlantic Current,...
| Main Authors: | , , , , , , , , , |
|---|---|
| Format: | Journal article |
| Language: | English |
| Published: |
Wiley
2024
|
| _version_ | 1817931351921262592 |
|---|---|
| author | Sanchez‐Franks, A Holliday, NP Evans, DG Fried, N Tooth, O Chafik, L Fu, Y Li, F de Jong, MF Johnson, HL |
| author_facet | Sanchez‐Franks, A Holliday, NP Evans, DG Fried, N Tooth, O Chafik, L Fu, Y Li, F de Jong, MF Johnson, HL |
| author_sort | Sanchez‐Franks, A |
| collection | OXFORD |
| description | The lower limb of the Atlantic meridional overturning circulation (AMOC) is the equatorward flow of dense waters formed through the cooling and freshening of the poleward-flowing upper limb. 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. Using observations from a SPNA mooring array, we show that variability of the AMOC's lower limb is connected to poleward flow in the interior Irminger Sea. We identify this poleward flow as the northward branch of the Irminger Gyre (IG), accounting for 55% of the AMOC's lower limb variability. Over 2014–2018, wind stress curl fluctuations over the Labrador and Irminger Seas drive this IG and AMOC variability. On longer (>annual) timescales, however, an increasing trend in the thickness of intermediate water, from 2014 to 2020, within the Irminger Sea coincides with a decreasing trend in IG strength. |
| first_indexed | 2024-12-09T03:20:39Z |
| format | Journal article |
| id | oxford-uuid:b921bb2b-364e-44fc-a1f3-ed821f3137d7 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-12-09T03:20:39Z |
| publishDate | 2024 |
| publisher | Wiley |
| record_format | dspace |
| spelling | oxford-uuid:b921bb2b-364e-44fc-a1f3-ed821f3137d72024-11-08T11:48:42ZThe Irminger Gyre as a key driver of the subpolar North Atlantic overturningJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:b921bb2b-364e-44fc-a1f3-ed821f3137d7EnglishSymplectic ElementsWiley2024Sanchez‐Franks, AHolliday, NPEvans, DGFried, NTooth, OChafik, LFu, YLi, Fde Jong, MFJohnson, HLThe lower limb of the Atlantic meridional overturning circulation (AMOC) is the equatorward flow of dense waters formed through the cooling and freshening of the poleward-flowing upper limb. 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. Using observations from a SPNA mooring array, we show that variability of the AMOC's lower limb is connected to poleward flow in the interior Irminger Sea. We identify this poleward flow as the northward branch of the Irminger Gyre (IG), accounting for 55% of the AMOC's lower limb variability. Over 2014–2018, wind stress curl fluctuations over the Labrador and Irminger Seas drive this IG and AMOC variability. On longer (>annual) timescales, however, an increasing trend in the thickness of intermediate water, from 2014 to 2020, within the Irminger Sea coincides with a decreasing trend in IG strength. |
| spellingShingle | Sanchez‐Franks, A Holliday, NP Evans, DG Fried, N Tooth, O Chafik, L Fu, Y Li, F de Jong, MF Johnson, HL The Irminger Gyre as a key driver of the subpolar North Atlantic overturning |
| title | The Irminger Gyre as a key driver of the subpolar North Atlantic overturning |
| title_full | The Irminger Gyre as a key driver of the subpolar North Atlantic overturning |
| title_fullStr | The Irminger Gyre as a key driver of the subpolar North Atlantic overturning |
| title_full_unstemmed | The Irminger Gyre as a key driver of the subpolar North Atlantic overturning |
| title_short | The Irminger Gyre as a key driver of the subpolar North Atlantic overturning |
| title_sort | irminger gyre as a key driver of the subpolar north atlantic overturning |
| work_keys_str_mv | AT sanchezfranksa theirmingergyreasakeydriverofthesubpolarnorthatlanticoverturning AT hollidaynp theirmingergyreasakeydriverofthesubpolarnorthatlanticoverturning AT evansdg theirmingergyreasakeydriverofthesubpolarnorthatlanticoverturning AT friedn theirmingergyreasakeydriverofthesubpolarnorthatlanticoverturning AT tootho theirmingergyreasakeydriverofthesubpolarnorthatlanticoverturning AT chafikl theirmingergyreasakeydriverofthesubpolarnorthatlanticoverturning AT fuy theirmingergyreasakeydriverofthesubpolarnorthatlanticoverturning AT lif theirmingergyreasakeydriverofthesubpolarnorthatlanticoverturning AT dejongmf theirmingergyreasakeydriverofthesubpolarnorthatlanticoverturning AT johnsonhl theirmingergyreasakeydriverofthesubpolarnorthatlanticoverturning AT sanchezfranksa irmingergyreasakeydriverofthesubpolarnorthatlanticoverturning AT hollidaynp irmingergyreasakeydriverofthesubpolarnorthatlanticoverturning AT evansdg irmingergyreasakeydriverofthesubpolarnorthatlanticoverturning AT friedn irmingergyreasakeydriverofthesubpolarnorthatlanticoverturning AT tootho irmingergyreasakeydriverofthesubpolarnorthatlanticoverturning AT chafikl irmingergyreasakeydriverofthesubpolarnorthatlanticoverturning AT fuy irmingergyreasakeydriverofthesubpolarnorthatlanticoverturning AT lif irmingergyreasakeydriverofthesubpolarnorthatlanticoverturning AT dejongmf irmingergyreasakeydriverofthesubpolarnorthatlanticoverturning AT johnsonhl irmingergyreasakeydriverofthesubpolarnorthatlanticoverturning |