Tracking water masses using passive-tracer transport in NEMO v3.4 with NEMOTAM: application to North Atlantic Deep Water and North Atlantic Subtropical Mode Water
Water mass ventilation provides an important link between the atmosphere and the global ocean circulation. In this study, we present a newly developed, probabilistic tool for offline water mass tracking. In particular, NEMOTAM, the tangent-linear and adjoint counterpart to the NEMO ocean general cir...
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ftdoajarticles:oai:doaj.org/article:0d5b644a999949adb93c2e6444e1bc87 2023-05-15T15:08:50+02:00 Tracking water masses using passive-tracer transport in NEMO v3.4 with NEMOTAM: application to North Atlantic Deep Water and North Atlantic Subtropical Mode Water D. Stephenson S. A. Müller F. Sévellec 2020-04-01T00:00:00Z https://doi.org/10.5194/gmd-13-2031-2020 https://doaj.org/article/0d5b644a999949adb93c2e6444e1bc87 EN eng Copernicus Publications https://www.geosci-model-dev.net/13/2031/2020/gmd-13-2031-2020.pdf https://doaj.org/toc/1991-959X https://doaj.org/toc/1991-9603 doi:10.5194/gmd-13-2031-2020 1991-959X 1991-9603 https://doaj.org/article/0d5b644a999949adb93c2e6444e1bc87 Geoscientific Model Development, Vol 13, Pp 2031-2050 (2020) Geology QE1-996.5 article 2020 ftdoajarticles https://doi.org/10.5194/gmd-13-2031-2020 2022-12-31T00:39:03Z Water mass ventilation provides an important link between the atmosphere and the global ocean circulation. In this study, we present a newly developed, probabilistic tool for offline water mass tracking. In particular, NEMOTAM, the tangent-linear and adjoint counterpart to the NEMO ocean general circulation model, is modified to allow passive-tracer transport. By terminating dynamic feedbacks in NEMOTAM, tagged water can be tracked forward and backward in time as a passive dye, producing a probability distribution of pathways and origins, respectively. To represent surface (re-)ventilation, we optionally decrease the tracer concentration in the surface layer and track this concentration removal to produce a ventilation record. Two test cases are detailed, examining the creation and fate of North Atlantic Subtropical Mode Water (NASMW) and North Atlantic Deep Water (NADW) in a 2 ∘ configuration of NEMO run with repeated annual forcing for up to 400 years. Model NASMW is shown to have an expected age of 4.5 years and is predominantly eradicated by internal processes. A bed of more persistent NASMW is detected below the mixed layer with an expected age of 8.7 years. It is shown that while model NADW has two distinct outcrops (in the Arctic and North Atlantic), its formation primarily takes place in the subpolar Labrador and Irminger seas. Its expected age is 112 years. Article in Journal/Newspaper Arctic NADW North Atlantic Deep Water North Atlantic Directory of Open Access Journals: DOAJ Articles Arctic Geoscientific Model Development 13 4 2031 2050 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Geology QE1-996.5 |
spellingShingle |
Geology QE1-996.5 D. Stephenson S. A. Müller F. Sévellec Tracking water masses using passive-tracer transport in NEMO v3.4 with NEMOTAM: application to North Atlantic Deep Water and North Atlantic Subtropical Mode Water |
topic_facet |
Geology QE1-996.5 |
description |
Water mass ventilation provides an important link between the atmosphere and the global ocean circulation. In this study, we present a newly developed, probabilistic tool for offline water mass tracking. In particular, NEMOTAM, the tangent-linear and adjoint counterpart to the NEMO ocean general circulation model, is modified to allow passive-tracer transport. By terminating dynamic feedbacks in NEMOTAM, tagged water can be tracked forward and backward in time as a passive dye, producing a probability distribution of pathways and origins, respectively. To represent surface (re-)ventilation, we optionally decrease the tracer concentration in the surface layer and track this concentration removal to produce a ventilation record. Two test cases are detailed, examining the creation and fate of North Atlantic Subtropical Mode Water (NASMW) and North Atlantic Deep Water (NADW) in a 2 ∘ configuration of NEMO run with repeated annual forcing for up to 400 years. Model NASMW is shown to have an expected age of 4.5 years and is predominantly eradicated by internal processes. A bed of more persistent NASMW is detected below the mixed layer with an expected age of 8.7 years. It is shown that while model NADW has two distinct outcrops (in the Arctic and North Atlantic), its formation primarily takes place in the subpolar Labrador and Irminger seas. Its expected age is 112 years. |
format |
Article in Journal/Newspaper |
author |
D. Stephenson S. A. Müller F. Sévellec |
author_facet |
D. Stephenson S. A. Müller F. Sévellec |
author_sort |
D. Stephenson |
title |
Tracking water masses using passive-tracer transport in NEMO v3.4 with NEMOTAM: application to North Atlantic Deep Water and North Atlantic Subtropical Mode Water |
title_short |
Tracking water masses using passive-tracer transport in NEMO v3.4 with NEMOTAM: application to North Atlantic Deep Water and North Atlantic Subtropical Mode Water |
title_full |
Tracking water masses using passive-tracer transport in NEMO v3.4 with NEMOTAM: application to North Atlantic Deep Water and North Atlantic Subtropical Mode Water |
title_fullStr |
Tracking water masses using passive-tracer transport in NEMO v3.4 with NEMOTAM: application to North Atlantic Deep Water and North Atlantic Subtropical Mode Water |
title_full_unstemmed |
Tracking water masses using passive-tracer transport in NEMO v3.4 with NEMOTAM: application to North Atlantic Deep Water and North Atlantic Subtropical Mode Water |
title_sort |
tracking water masses using passive-tracer transport in nemo v3.4 with nemotam: application to north atlantic deep water and north atlantic subtropical mode water |
publisher |
Copernicus Publications |
publishDate |
2020 |
url |
https://doi.org/10.5194/gmd-13-2031-2020 https://doaj.org/article/0d5b644a999949adb93c2e6444e1bc87 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic NADW North Atlantic Deep Water North Atlantic |
genre_facet |
Arctic NADW North Atlantic Deep Water North Atlantic |
op_source |
Geoscientific Model Development, Vol 13, Pp 2031-2050 (2020) |
op_relation |
https://www.geosci-model-dev.net/13/2031/2020/gmd-13-2031-2020.pdf https://doaj.org/toc/1991-959X https://doaj.org/toc/1991-9603 doi:10.5194/gmd-13-2031-2020 1991-959X 1991-9603 https://doaj.org/article/0d5b644a999949adb93c2e6444e1bc87 |
op_doi |
https://doi.org/10.5194/gmd-13-2031-2020 |
container_title |
Geoscientific Model Development |
container_volume |
13 |
container_issue |
4 |
container_start_page |
2031 |
op_container_end_page |
2050 |
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1766340122684424192 |