Sub-basin-scale sea level budgets from satellite altimetry, Argo floats and satellite gravimetry: a case study in the North Atlantic Ocean
In this study, for the first time, an attempt is made to close the sea level budget on a sub-basin scale in terms of trend and amplitude of the annual cycle. We also compare the residual time series after removing the trend, the semiannual and the annual signals. To obtain errors for altimetry and A...
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ftdoajarticles:oai:doaj.org/article:59d76aa455ed499d847053b02b2a277b 2023-05-15T17:32:34+02:00 Sub-basin-scale sea level budgets from satellite altimetry, Argo floats and satellite gravimetry: a case study in the North Atlantic Ocean M. Kleinherenbrink R. Riva Y. Sun 2016-11-01T00:00:00Z https://doi.org/10.5194/os-12-1179-2016 https://doaj.org/article/59d76aa455ed499d847053b02b2a277b EN eng Copernicus Publications http://www.ocean-sci.net/12/1179/2016/os-12-1179-2016.pdf https://doaj.org/toc/1812-0784 https://doaj.org/toc/1812-0792 1812-0784 1812-0792 doi:10.5194/os-12-1179-2016 https://doaj.org/article/59d76aa455ed499d847053b02b2a277b Ocean Science, Vol 12, Iss 6, Pp 1179-1203 (2016) Geography. Anthropology. Recreation G Environmental sciences GE1-350 article 2016 ftdoajarticles https://doi.org/10.5194/os-12-1179-2016 2022-12-31T00:34:31Z In this study, for the first time, an attempt is made to close the sea level budget on a sub-basin scale in terms of trend and amplitude of the annual cycle. We also compare the residual time series after removing the trend, the semiannual and the annual signals. To obtain errors for altimetry and Argo, full variance–covariance matrices are computed using correlation functions and their errors are fully propagated. For altimetry, we apply a geographically dependent intermission bias [Ablain et al.(2015)], which leads to differences in trends up to 0.8 mm yr −1 . Since Argo float measurements are non-homogeneously spaced, steric sea levels are first objectively interpolated onto a grid before averaging. For the Gravity Recovery And Climate Experiment (GRACE), gravity fields full variance–covariance matrices are used to propagate errors and statistically filter the gravity fields. We use four different filtered gravity field solutions and determine which post-processing strategy is best for budget closure. As a reference, the standard 96 degree Dense Decorrelation Kernel-5 (DDK5)-filtered Center for Space Research (CSR) solution is used to compute the mass component (MC). A comparison is made with two anisotropic Wiener-filtered CSR solutions up to degree and order 60 and 96 and a Wiener-filtered 90 degree ITSG solution. Budgets are computed for 10 polygons in the North Atlantic Ocean, defined in a way that the error on the trend of the MC plus steric sea level remains within 1 mm yr −1 . Using the anisotropic Wiener filter on CSR gravity fields expanded up to spherical harmonic degree 96, it is possible to close the sea level budget in 9 of 10 sub-basins in terms of trend. Wiener-filtered Institute of Theoretical geodesy and Satellite Geodesy (ITSG) and the standard DDK5-filtered CSR solutions also close the trend budget if a glacial isostatic adjustment (GIA) correction error of 10–20 % is applied; however, the performance of the DDK5-filtered solution strongly depends on the orientation of the polygon due to ... Article in Journal/Newspaper North Atlantic Directory of Open Access Journals: DOAJ Articles Ocean Science 12 6 1179 1203 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Geography. Anthropology. Recreation G Environmental sciences GE1-350 |
spellingShingle |
Geography. Anthropology. Recreation G Environmental sciences GE1-350 M. Kleinherenbrink R. Riva Y. Sun Sub-basin-scale sea level budgets from satellite altimetry, Argo floats and satellite gravimetry: a case study in the North Atlantic Ocean |
topic_facet |
Geography. Anthropology. Recreation G Environmental sciences GE1-350 |
description |
In this study, for the first time, an attempt is made to close the sea level budget on a sub-basin scale in terms of trend and amplitude of the annual cycle. We also compare the residual time series after removing the trend, the semiannual and the annual signals. To obtain errors for altimetry and Argo, full variance–covariance matrices are computed using correlation functions and their errors are fully propagated. For altimetry, we apply a geographically dependent intermission bias [Ablain et al.(2015)], which leads to differences in trends up to 0.8 mm yr −1 . Since Argo float measurements are non-homogeneously spaced, steric sea levels are first objectively interpolated onto a grid before averaging. For the Gravity Recovery And Climate Experiment (GRACE), gravity fields full variance–covariance matrices are used to propagate errors and statistically filter the gravity fields. We use four different filtered gravity field solutions and determine which post-processing strategy is best for budget closure. As a reference, the standard 96 degree Dense Decorrelation Kernel-5 (DDK5)-filtered Center for Space Research (CSR) solution is used to compute the mass component (MC). A comparison is made with two anisotropic Wiener-filtered CSR solutions up to degree and order 60 and 96 and a Wiener-filtered 90 degree ITSG solution. Budgets are computed for 10 polygons in the North Atlantic Ocean, defined in a way that the error on the trend of the MC plus steric sea level remains within 1 mm yr −1 . Using the anisotropic Wiener filter on CSR gravity fields expanded up to spherical harmonic degree 96, it is possible to close the sea level budget in 9 of 10 sub-basins in terms of trend. Wiener-filtered Institute of Theoretical geodesy and Satellite Geodesy (ITSG) and the standard DDK5-filtered CSR solutions also close the trend budget if a glacial isostatic adjustment (GIA) correction error of 10–20 % is applied; however, the performance of the DDK5-filtered solution strongly depends on the orientation of the polygon due to ... |
format |
Article in Journal/Newspaper |
author |
M. Kleinherenbrink R. Riva Y. Sun |
author_facet |
M. Kleinherenbrink R. Riva Y. Sun |
author_sort |
M. Kleinherenbrink |
title |
Sub-basin-scale sea level budgets from satellite altimetry, Argo floats and satellite gravimetry: a case study in the North Atlantic Ocean |
title_short |
Sub-basin-scale sea level budgets from satellite altimetry, Argo floats and satellite gravimetry: a case study in the North Atlantic Ocean |
title_full |
Sub-basin-scale sea level budgets from satellite altimetry, Argo floats and satellite gravimetry: a case study in the North Atlantic Ocean |
title_fullStr |
Sub-basin-scale sea level budgets from satellite altimetry, Argo floats and satellite gravimetry: a case study in the North Atlantic Ocean |
title_full_unstemmed |
Sub-basin-scale sea level budgets from satellite altimetry, Argo floats and satellite gravimetry: a case study in the North Atlantic Ocean |
title_sort |
sub-basin-scale sea level budgets from satellite altimetry, argo floats and satellite gravimetry: a case study in the north atlantic ocean |
publisher |
Copernicus Publications |
publishDate |
2016 |
url |
https://doi.org/10.5194/os-12-1179-2016 https://doaj.org/article/59d76aa455ed499d847053b02b2a277b |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Ocean Science, Vol 12, Iss 6, Pp 1179-1203 (2016) |
op_relation |
http://www.ocean-sci.net/12/1179/2016/os-12-1179-2016.pdf https://doaj.org/toc/1812-0784 https://doaj.org/toc/1812-0792 1812-0784 1812-0792 doi:10.5194/os-12-1179-2016 https://doaj.org/article/59d76aa455ed499d847053b02b2a277b |
op_doi |
https://doi.org/10.5194/os-12-1179-2016 |
container_title |
Ocean Science |
container_volume |
12 |
container_issue |
6 |
container_start_page |
1179 |
op_container_end_page |
1203 |
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1766130764279185408 |