Response of subpolar North Atlantic meridional overturning circulation to variability in surface winds on different timescales
<p>A large part of the variability in the Atlantic meridional overturning circulation (AMOC) and thus uncertainty in its estimates on interannual time scales comes from atmospheric synoptic eddies and mesoscale processes. In this study, a suite of experiments with a 1/12° regional configuratio...
| Main Authors: | , , |
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| Formato: | Journal article |
| Idioma: | English |
| Publicado: |
American Meteorological Society
2024
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| _version_ | 1826314689188986880 |
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| author | Markina, MY Johnson, HL Marshall, DP |
| author_facet | Markina, MY Johnson, HL Marshall, DP |
| author_sort | Markina, MY |
| collection | OXFORD |
| description | <p>A large part of the variability in the Atlantic meridional overturning circulation (AMOC) and thus uncertainty in its estimates on interannual time scales comes from atmospheric synoptic eddies and mesoscale processes. In this study, a suite of experiments with a 1/12° regional configuration of the MITgcm is performed where low-pass filtering is applied to surface wind forcing to investigate the impact of subsynoptic (<2 days) and synoptic (2–10 days) atmospheric processes on the ocean circulation. Changes in the wind magnitude and hence the wind energy input in the region have a significant effect on the strength of the overturning; once this is accounted for, the magnitude of the overturning in all sensitivity experiments is very similar to that of the control run. Synoptic and subsynoptic variability in atmospheric winds reduce the surface heat loss in the Labrador Sea, resulting in anomalous advection of warm and salty waters into the Irminger Sea and lower upper-ocean densities in the eastern subpolar North Atlantic. Other effects of high-frequency variability in surface winds on the AMOC are associated with changes in Ekman convergence in the midlatitudes. Synoptic and subsynoptic winds also impact the strength of the boundary currents and density structure in the subpolar North Atlantic. In the Labrador Sea, the overturning strength is more sensitive to the changes in density structure, whereas in the eastern subpolar North Atlantic, the role of density is comparable to that of the strength of the East Greenland Current.</p> |
| first_indexed | 2024-09-25T04:13:37Z |
| format | Journal article |
| id | oxford-uuid:40ad8abc-f8a4-48c0-9a68-c25e10ff8a6e |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-12-09T03:11:27Z |
| publishDate | 2024 |
| publisher | American Meteorological Society |
| record_format | dspace |
| spelling | oxford-uuid:40ad8abc-f8a4-48c0-9a68-c25e10ff8a6e2024-10-10T13:01:05ZResponse of subpolar North Atlantic meridional overturning circulation to variability in surface winds on different timescalesJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:40ad8abc-f8a4-48c0-9a68-c25e10ff8a6eEnglishSymplectic ElementsAmerican Meteorological Society2024Markina, MYJohnson, HLMarshall, DP<p>A large part of the variability in the Atlantic meridional overturning circulation (AMOC) and thus uncertainty in its estimates on interannual time scales comes from atmospheric synoptic eddies and mesoscale processes. In this study, a suite of experiments with a 1/12° regional configuration of the MITgcm is performed where low-pass filtering is applied to surface wind forcing to investigate the impact of subsynoptic (<2 days) and synoptic (2–10 days) atmospheric processes on the ocean circulation. Changes in the wind magnitude and hence the wind energy input in the region have a significant effect on the strength of the overturning; once this is accounted for, the magnitude of the overturning in all sensitivity experiments is very similar to that of the control run. Synoptic and subsynoptic variability in atmospheric winds reduce the surface heat loss in the Labrador Sea, resulting in anomalous advection of warm and salty waters into the Irminger Sea and lower upper-ocean densities in the eastern subpolar North Atlantic. Other effects of high-frequency variability in surface winds on the AMOC are associated with changes in Ekman convergence in the midlatitudes. Synoptic and subsynoptic winds also impact the strength of the boundary currents and density structure in the subpolar North Atlantic. In the Labrador Sea, the overturning strength is more sensitive to the changes in density structure, whereas in the eastern subpolar North Atlantic, the role of density is comparable to that of the strength of the East Greenland Current.</p> |
| spellingShingle | Markina, MY Johnson, HL Marshall, DP Response of subpolar North Atlantic meridional overturning circulation to variability in surface winds on different timescales |
| title | Response of subpolar North Atlantic meridional overturning circulation to variability in surface winds on different timescales |
| title_full | Response of subpolar North Atlantic meridional overturning circulation to variability in surface winds on different timescales |
| title_fullStr | Response of subpolar North Atlantic meridional overturning circulation to variability in surface winds on different timescales |
| title_full_unstemmed | Response of subpolar North Atlantic meridional overturning circulation to variability in surface winds on different timescales |
| title_short | Response of subpolar North Atlantic meridional overturning circulation to variability in surface winds on different timescales |
| title_sort | response of subpolar north atlantic meridional overturning circulation to variability in surface winds on different timescales |
| work_keys_str_mv | AT markinamy responseofsubpolarnorthatlanticmeridionaloverturningcirculationtovariabilityinsurfacewindsondifferenttimescales AT johnsonhl responseofsubpolarnorthatlanticmeridionaloverturningcirculationtovariabilityinsurfacewindsondifferenttimescales AT marshalldp responseofsubpolarnorthatlanticmeridionaloverturningcirculationtovariabilityinsurfacewindsondifferenttimescales |