Mean circulation and EKE distribution in the Labrador Sea Water level of the subpolar North Atlantic
A long-term mean flow field for the subpolar North Atlantic region with a horizontal resolution of approximately 25km is created by gridding Argo-derived velocity vectors using two different topography-following interpolation schemes. The 10-day float displacements in the typical drift depths of 100...
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Copernicus Publications (EGU)
2018
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Online Access: | https://oceanrep.geomar.de/id/eprint/43117/ https://oceanrep.geomar.de/id/eprint/43117/1/os-14-1167-2018.pdf https://doi.org/10.5194/os-14-1167-2018 |
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ftoceanrep:oai:oceanrep.geomar.de:43117 2023-05-15T16:48:49+02:00 Mean circulation and EKE distribution in the Labrador Sea Water level of the subpolar North Atlantic Fischer, Jürgen Karstensen, Johannes Oltmanns, Marilena Schmidtko, Sunke 2018-10-05 text https://oceanrep.geomar.de/id/eprint/43117/ https://oceanrep.geomar.de/id/eprint/43117/1/os-14-1167-2018.pdf https://doi.org/10.5194/os-14-1167-2018 en eng Copernicus Publications (EGU) https://oceanrep.geomar.de/id/eprint/43117/1/os-14-1167-2018.pdf Fischer, J. , Karstensen, J. , Oltmanns, M. and Schmidtko, S. (2018) Mean circulation and EKE distribution in the Labrador Sea Water level of the subpolar North Atlantic. Open Access Ocean Science, 14 . pp. 1167-1183. DOI 10.5194/os-14-1167-2018 <https://doi.org/10.5194/os-14-1167-2018>. doi:10.5194/os-14-1167-2018 cc_by_3.0 info:eu-repo/semantics/openAccess Article PeerReviewed info:eu-repo/semantics/article 2018 ftoceanrep https://doi.org/10.5194/os-14-1167-2018 2023-04-07T15:39:51Z A long-term mean flow field for the subpolar North Atlantic region with a horizontal resolution of approximately 25km is created by gridding Argo-derived velocity vectors using two different topography-following interpolation schemes. The 10-day float displacements in the typical drift depths of 1000 to 1500m represent the flow in the Labrador Sea Water density range. Both mapping algorithms separate the flow field into potential vorticity (PV) conserving, i.e., topography-following contribution and a deviating part, which we define as the eddy contribution. To verify the significance of the separation, we compare the mean flow and the eddy kinetic energy (EKE), derived from both mapping algorithms, with those obtained from multiyear mooring observations. The PV-conserving mean flow is characterized by stable boundary currents along all major topographic features including shelf breaks and basin-interior topographic ridges such as the Reykjanes Ridge or the Rockall Plateau. Mid-basin northward advection pathways from the northeastern Labrador Sea into the Irminger Sea and from the Mid-Atlantic Ridge region into the Iceland Basin are well-resolved. An eastward flow is present across the southern boundary of the subpolar gyre near 52°N, the latitude of the Charlie Gibbs Fracture Zone (CGFZ). The mid-depth EKE field resembles most of the satellite-derived surface EKE field. However, noticeable differences exist along the northward advection pathways in the Irminger Sea and the Iceland Basin, where the deep EKE exceeds the surface EKE field. Further, the ratio between mean flow and the square root of the EKE, the Peclet number, reveals distinct advection-dominated regions as well as basin-interior regimes in which mixing is prevailing. Article in Journal/Newspaper Iceland Labrador Sea North Atlantic OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Irminger Sea ENVELOPE(-34.041,-34.041,63.054,63.054) Mid-Atlantic Ridge Reykjanes ENVELOPE(-22.250,-22.250,65.467,65.467) Rockall Plateau ENVELOPE(-18.833,-18.833,56.333,56.333) Ocean Science 14 5 1167 1183 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
A long-term mean flow field for the subpolar North Atlantic region with a horizontal resolution of approximately 25km is created by gridding Argo-derived velocity vectors using two different topography-following interpolation schemes. The 10-day float displacements in the typical drift depths of 1000 to 1500m represent the flow in the Labrador Sea Water density range. Both mapping algorithms separate the flow field into potential vorticity (PV) conserving, i.e., topography-following contribution and a deviating part, which we define as the eddy contribution. To verify the significance of the separation, we compare the mean flow and the eddy kinetic energy (EKE), derived from both mapping algorithms, with those obtained from multiyear mooring observations. The PV-conserving mean flow is characterized by stable boundary currents along all major topographic features including shelf breaks and basin-interior topographic ridges such as the Reykjanes Ridge or the Rockall Plateau. Mid-basin northward advection pathways from the northeastern Labrador Sea into the Irminger Sea and from the Mid-Atlantic Ridge region into the Iceland Basin are well-resolved. An eastward flow is present across the southern boundary of the subpolar gyre near 52°N, the latitude of the Charlie Gibbs Fracture Zone (CGFZ). The mid-depth EKE field resembles most of the satellite-derived surface EKE field. However, noticeable differences exist along the northward advection pathways in the Irminger Sea and the Iceland Basin, where the deep EKE exceeds the surface EKE field. Further, the ratio between mean flow and the square root of the EKE, the Peclet number, reveals distinct advection-dominated regions as well as basin-interior regimes in which mixing is prevailing. |
format |
Article in Journal/Newspaper |
author |
Fischer, Jürgen Karstensen, Johannes Oltmanns, Marilena Schmidtko, Sunke |
spellingShingle |
Fischer, Jürgen Karstensen, Johannes Oltmanns, Marilena Schmidtko, Sunke Mean circulation and EKE distribution in the Labrador Sea Water level of the subpolar North Atlantic |
author_facet |
Fischer, Jürgen Karstensen, Johannes Oltmanns, Marilena Schmidtko, Sunke |
author_sort |
Fischer, Jürgen |
title |
Mean circulation and EKE distribution in the Labrador Sea Water level of the subpolar North Atlantic |
title_short |
Mean circulation and EKE distribution in the Labrador Sea Water level of the subpolar North Atlantic |
title_full |
Mean circulation and EKE distribution in the Labrador Sea Water level of the subpolar North Atlantic |
title_fullStr |
Mean circulation and EKE distribution in the Labrador Sea Water level of the subpolar North Atlantic |
title_full_unstemmed |
Mean circulation and EKE distribution in the Labrador Sea Water level of the subpolar North Atlantic |
title_sort |
mean circulation and eke distribution in the labrador sea water level of the subpolar north atlantic |
publisher |
Copernicus Publications (EGU) |
publishDate |
2018 |
url |
https://oceanrep.geomar.de/id/eprint/43117/ https://oceanrep.geomar.de/id/eprint/43117/1/os-14-1167-2018.pdf https://doi.org/10.5194/os-14-1167-2018 |
long_lat |
ENVELOPE(-34.041,-34.041,63.054,63.054) ENVELOPE(-22.250,-22.250,65.467,65.467) ENVELOPE(-18.833,-18.833,56.333,56.333) |
geographic |
Irminger Sea Mid-Atlantic Ridge Reykjanes Rockall Plateau |
geographic_facet |
Irminger Sea Mid-Atlantic Ridge Reykjanes Rockall Plateau |
genre |
Iceland Labrador Sea North Atlantic |
genre_facet |
Iceland Labrador Sea North Atlantic |
op_relation |
https://oceanrep.geomar.de/id/eprint/43117/1/os-14-1167-2018.pdf Fischer, J. , Karstensen, J. , Oltmanns, M. and Schmidtko, S. (2018) Mean circulation and EKE distribution in the Labrador Sea Water level of the subpolar North Atlantic. Open Access Ocean Science, 14 . pp. 1167-1183. DOI 10.5194/os-14-1167-2018 <https://doi.org/10.5194/os-14-1167-2018>. doi:10.5194/os-14-1167-2018 |
op_rights |
cc_by_3.0 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/os-14-1167-2018 |
container_title |
Ocean Science |
container_volume |
14 |
container_issue |
5 |
container_start_page |
1167 |
op_container_end_page |
1183 |
_version_ |
1766038917893586944 |