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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ftcopernicus:oai:publications.copernicus.org:os25048 2023-05-15T17:43:26+02:00 Constraining energetic slope currents through assimilation of high-frequency radar observations Sperrevik, A. K. Christensen, K. H. Röhrs, J. 2018-01-15 application/pdf https://doi.org/10.5194/os-11-237-2015 https://os.copernicus.org/articles/11/237/2015/ eng eng doi:10.5194/os-11-237-2015 https://os.copernicus.org/articles/11/237/2015/ eISSN: 1812-0792 Text 2018 ftcopernicus https://doi.org/10.5194/os-11-237-2015 2020-07-20T16:24:43Z 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. Text Northern Norway Vesterålen Copernicus Publications: E-Journals Norway Vesterålen ENVELOPE(14.939,14.939,68.754,68.754) Ocean Science 11 2 237 249 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
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. |
format |
Text |
author |
Sperrevik, A. K. Christensen, K. H. Röhrs, J. |
spellingShingle |
Sperrevik, A. K. Christensen, K. H. Röhrs, J. Constraining energetic slope currents through assimilation of high-frequency radar observations |
author_facet |
Sperrevik, A. K. Christensen, K. H. Röhrs, J. |
author_sort |
Sperrevik, A. K. |
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 |
publishDate |
2018 |
url |
https://doi.org/10.5194/os-11-237-2015 https://os.copernicus.org/articles/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 |
eISSN: 1812-0792 |
op_relation |
doi:10.5194/os-11-237-2015 https://os.copernicus.org/articles/11/237/2015/ |
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_ |
1766145501027106816 |