Constraining energetic slope currents through assimilation of high-frequency radar observations
Assimilation of high-frequency (HF) radar current observations and CTD hydrography is performed with the 4D-Var analysis scheme implemented in the Regional Ocean Modeling System (ROMS). We consider both an idealized case, with a baroclinic slope current in a periodic channel, and a realistic case fo...
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Online Access: | https://hdl.handle.net/1956/16173 https://doi.org/10.5194/os-11-237-2015 |
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ftunivbergen:oai:bora.uib.no:1956/16173 2023-05-15T17:43:26+02:00 Constraining energetic slope currents through assimilation of high-frequency radar observations Sperrevik, Ann Kristin Christensen, Kai Håkon Röhrs, Johannes 2015-03-11 application/pdf https://hdl.handle.net/1956/16173 https://doi.org/10.5194/os-11-237-2015 eng eng Copernicus Modeling coastal circulation in Norway using a high-resolution 4D-Var ocean assimilation system urn:issn:1812-0784 https://hdl.handle.net/1956/16173 https://doi.org/10.5194/os-11-237-2015 cristin:1340314 Attribution CC BY http://creativecommons.org/licenses/by/3.0/ Copyright 2015 The Authors Ocean Science 11 2 237-249 Peer reviewed Journal article 2015 ftunivbergen https://doi.org/10.5194/os-11-237-2015 2023-03-14T17:42:10Z Assimilation of high-frequency (HF) radar current observations and CTD hydrography is performed with the 4D-Var analysis scheme implemented in the Regional Ocean Modeling System (ROMS). We consider both an idealized case, with a baroclinic slope current in a periodic channel, and a realistic case for the coast of Vesterålen in northern Norway. In the realistic case, the results of the data assimilation are compared with independent data from acoustic profilers and surface drifters. Best results are obtained when background error correlation scales are small (10 km or less) and when the data assimilation window is short, i.e. about 1 day. Furthermore, we find that the impact of assimilating HF radar currents is generally larger than the impact of CTD hydrography. However, combining the HF radar currents with a few hydrographic profiles gives significantly better results, which demonstrates the importance of complementing surface observations with observations of the vertical structure of the ocean. publishedVersion Article in Journal/Newspaper Northern Norway Vesterålen University of Bergen: Bergen Open Research Archive (BORA-UiB) Norway Vesterålen ENVELOPE(14.939,14.939,68.754,68.754) Ocean Science 11 2 237 249 |
institution |
Open Polar |
collection |
University of Bergen: Bergen Open Research Archive (BORA-UiB) |
op_collection_id |
ftunivbergen |
language |
English |
description |
Assimilation of high-frequency (HF) radar current observations and CTD hydrography is performed with the 4D-Var analysis scheme implemented in the Regional Ocean Modeling System (ROMS). We consider both an idealized case, with a baroclinic slope current in a periodic channel, and a realistic case for the coast of Vesterålen in northern Norway. In the realistic case, the results of the data assimilation are compared with independent data from acoustic profilers and surface drifters. Best results are obtained when background error correlation scales are small (10 km or less) and when the data assimilation window is short, i.e. about 1 day. Furthermore, we find that the impact of assimilating HF radar currents is generally larger than the impact of CTD hydrography. However, combining the HF radar currents with a few hydrographic profiles gives significantly better results, which demonstrates the importance of complementing surface observations with observations of the vertical structure of the ocean. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Sperrevik, Ann Kristin Christensen, Kai Håkon Röhrs, Johannes |
spellingShingle |
Sperrevik, Ann Kristin Christensen, Kai Håkon Röhrs, Johannes Constraining energetic slope currents through assimilation of high-frequency radar observations |
author_facet |
Sperrevik, Ann Kristin Christensen, Kai Håkon Röhrs, Johannes |
author_sort |
Sperrevik, Ann Kristin |
title |
Constraining energetic slope currents through assimilation of high-frequency radar observations |
title_short |
Constraining energetic slope currents through assimilation of high-frequency radar observations |
title_full |
Constraining energetic slope currents through assimilation of high-frequency radar observations |
title_fullStr |
Constraining energetic slope currents through assimilation of high-frequency radar observations |
title_full_unstemmed |
Constraining energetic slope currents through assimilation of high-frequency radar observations |
title_sort |
constraining energetic slope currents through assimilation of high-frequency radar observations |
publisher |
Copernicus |
publishDate |
2015 |
url |
https://hdl.handle.net/1956/16173 https://doi.org/10.5194/os-11-237-2015 |
long_lat |
ENVELOPE(14.939,14.939,68.754,68.754) |
geographic |
Norway Vesterålen |
geographic_facet |
Norway Vesterålen |
genre |
Northern Norway Vesterålen |
genre_facet |
Northern Norway Vesterålen |
op_source |
Ocean Science 11 2 237-249 |
op_relation |
Modeling coastal circulation in Norway using a high-resolution 4D-Var ocean assimilation system urn:issn:1812-0784 https://hdl.handle.net/1956/16173 https://doi.org/10.5194/os-11-237-2015 cristin:1340314 |
op_rights |
Attribution CC BY http://creativecommons.org/licenses/by/3.0/ Copyright 2015 The Authors |
op_doi |
https://doi.org/10.5194/os-11-237-2015 |
container_title |
Ocean Science |
container_volume |
11 |
container_issue |
2 |
container_start_page |
237 |
op_container_end_page |
249 |
_version_ |
1766145499198390272 |