The effects of atmospheric and lateral buoyancy fluxes on Labrador Sea mixed layer depth
The depth of the Labrador Sea mixed layer during winter convection is a balance between atmospheric buoyancy loss and lateral buoyancy exchange, and is notoriously difficult to represent accurately in ocean and climate models. This study shows that lateral exchanges of heat and salt between the shel...
Published in: | Ocean Modelling |
---|---|
Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Elsevier
2022
|
Subjects: | |
Online Access: | https://oceanrep.geomar.de/id/eprint/56979/ https://oceanrep.geomar.de/id/eprint/56979/1/Gillard.pdf https://doi.org/10.1016/j.ocemod.2022.101974 |
id |
ftoceanrep:oai:oceanrep.geomar.de:56979 |
---|---|
record_format |
openpolar |
spelling |
ftoceanrep:oai:oceanrep.geomar.de:56979 2023-05-15T15:51:50+02:00 The effects of atmospheric and lateral buoyancy fluxes on Labrador Sea mixed layer depth Gillard, Laura C. Pennelly, Clark Johnson, Helen L. Myers, Paul G. 2022-03 text https://oceanrep.geomar.de/id/eprint/56979/ https://oceanrep.geomar.de/id/eprint/56979/1/Gillard.pdf https://doi.org/10.1016/j.ocemod.2022.101974 en eng Elsevier https://oceanrep.geomar.de/id/eprint/56979/1/Gillard.pdf Gillard, L. C., Pennelly, C., Johnson, H. L. and Myers, P. G. (2022) The effects of atmospheric and lateral buoyancy fluxes on Labrador Sea mixed layer depth. Ocean Modelling, 171 . Art.-Nr.: 101974. DOI 10.1016/j.ocemod.2022.101974 <https://doi.org/10.1016/j.ocemod.2022.101974>. doi:10.1016/j.ocemod.2022.101974 info:eu-repo/semantics/restrictedAccess Article PeerReviewed 2022 ftoceanrep https://doi.org/10.1016/j.ocemod.2022.101974 2023-04-07T16:04:31Z The depth of the Labrador Sea mixed layer during winter convection is a balance between atmospheric buoyancy loss and lateral buoyancy exchange, and is notoriously difficult to represent accurately in ocean and climate models. This study shows that lateral exchanges of heat and salt between the shelf and the interior are smaller in a regional coupled ocean–sea ice model at higher vertical resolution (75 levels compared with 50 levels), due in part to altered bathymetry along the Greenland shelf. Reduced lateral exchange results in a stronger stratification in the interior of the Labrador Sea, with stronger convection resistance which results in unrealistically shallow mixed layers. The westward fluxes of heat and salt associated with Irminger Water at Cape Farewell are 50 % and 33 % lower, respectively, with higher vertical resolution. Exchanges south of the Labrador Sea from the North Atlantic Current are also smaller, contributing to a reduction in salt and heat import into the Labrador Sea interior. When the high resolution model is forced with a stronger wintertime buoyancy loss at the ocean surface, this weakens the Labrador Sea stratification, allowing the forcing to break through the freshwater cap and increasing convection, bringing mixed layer depths back to observed values. A strong atmospheric forcing can therefore compensate for a reduction in lateral advection. The mixed layer depths, which are representative of convection and Labrador Sea water formation, will be the focus in this study. Therefore, this study suggests that convection and Labrador Sea Water formation is a complex interplay of surface and lateral fluxes, linked to stratification thresholds. Article in Journal/Newspaper Cape Farewell Greenland Labrador Sea north atlantic current North Atlantic Sea ice OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Greenland Ocean Modelling 171 101974 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
The depth of the Labrador Sea mixed layer during winter convection is a balance between atmospheric buoyancy loss and lateral buoyancy exchange, and is notoriously difficult to represent accurately in ocean and climate models. This study shows that lateral exchanges of heat and salt between the shelf and the interior are smaller in a regional coupled ocean–sea ice model at higher vertical resolution (75 levels compared with 50 levels), due in part to altered bathymetry along the Greenland shelf. Reduced lateral exchange results in a stronger stratification in the interior of the Labrador Sea, with stronger convection resistance which results in unrealistically shallow mixed layers. The westward fluxes of heat and salt associated with Irminger Water at Cape Farewell are 50 % and 33 % lower, respectively, with higher vertical resolution. Exchanges south of the Labrador Sea from the North Atlantic Current are also smaller, contributing to a reduction in salt and heat import into the Labrador Sea interior. When the high resolution model is forced with a stronger wintertime buoyancy loss at the ocean surface, this weakens the Labrador Sea stratification, allowing the forcing to break through the freshwater cap and increasing convection, bringing mixed layer depths back to observed values. A strong atmospheric forcing can therefore compensate for a reduction in lateral advection. The mixed layer depths, which are representative of convection and Labrador Sea water formation, will be the focus in this study. Therefore, this study suggests that convection and Labrador Sea Water formation is a complex interplay of surface and lateral fluxes, linked to stratification thresholds. |
format |
Article in Journal/Newspaper |
author |
Gillard, Laura C. Pennelly, Clark Johnson, Helen L. Myers, Paul G. |
spellingShingle |
Gillard, Laura C. Pennelly, Clark Johnson, Helen L. Myers, Paul G. The effects of atmospheric and lateral buoyancy fluxes on Labrador Sea mixed layer depth |
author_facet |
Gillard, Laura C. Pennelly, Clark Johnson, Helen L. Myers, Paul G. |
author_sort |
Gillard, Laura C. |
title |
The effects of atmospheric and lateral buoyancy fluxes on Labrador Sea mixed layer depth |
title_short |
The effects of atmospheric and lateral buoyancy fluxes on Labrador Sea mixed layer depth |
title_full |
The effects of atmospheric and lateral buoyancy fluxes on Labrador Sea mixed layer depth |
title_fullStr |
The effects of atmospheric and lateral buoyancy fluxes on Labrador Sea mixed layer depth |
title_full_unstemmed |
The effects of atmospheric and lateral buoyancy fluxes on Labrador Sea mixed layer depth |
title_sort |
effects of atmospheric and lateral buoyancy fluxes on labrador sea mixed layer depth |
publisher |
Elsevier |
publishDate |
2022 |
url |
https://oceanrep.geomar.de/id/eprint/56979/ https://oceanrep.geomar.de/id/eprint/56979/1/Gillard.pdf https://doi.org/10.1016/j.ocemod.2022.101974 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Cape Farewell Greenland Labrador Sea north atlantic current North Atlantic Sea ice |
genre_facet |
Cape Farewell Greenland Labrador Sea north atlantic current North Atlantic Sea ice |
op_relation |
https://oceanrep.geomar.de/id/eprint/56979/1/Gillard.pdf Gillard, L. C., Pennelly, C., Johnson, H. L. and Myers, P. G. (2022) The effects of atmospheric and lateral buoyancy fluxes on Labrador Sea mixed layer depth. Ocean Modelling, 171 . Art.-Nr.: 101974. DOI 10.1016/j.ocemod.2022.101974 <https://doi.org/10.1016/j.ocemod.2022.101974>. doi:10.1016/j.ocemod.2022.101974 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1016/j.ocemod.2022.101974 |
container_title |
Ocean Modelling |
container_volume |
171 |
container_start_page |
101974 |
_version_ |
1766387222728146944 |