Estimates of sea surface height and near-surface alongshore coastal currents from combinations of altimeters and tide gauges

Present methods used to retrieve altimeter data do not provide reliable estimates of sea surface height (SSH) in the nearshore region, resulting in a measurement gap of 25-50 km next to the coast. In the present work, gridded SSH fields produced by Archiving, Validation, and Interpretation of Satell...

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Autores principales: Saraceno, M., Strub, P.T., Kosro, P.M.
Formato: JOUR
Materias:
Ocean currents
Oceanography
Tide gages
Time series analysis
coastal current
nearshore dynamics
satellite altimetry
satellite data
sea surface height
tide gauge
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_21699291_v113_n11_p_Saraceno
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
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spelling todo:paper_21699291_v113_n11_p_Saraceno2023-10-03T16:39:53Z Estimates of sea surface height and near-surface alongshore coastal currents from combinations of altimeters and tide gauges Saraceno, M. Strub, P.T. Kosro, P.M. Ocean currents Oceanography Tide gages Time series analysis coastal current nearshore dynamics satellite altimetry satellite data sea surface height tide gauge Present methods used to retrieve altimeter data do not provide reliable estimates of sea surface height (SSH) in the nearshore region, resulting in a measurement gap of 25-50 km next to the coast. In the present work, gridded SSH fields produced by Archiving, Validation, and Interpretation of Satellite Oceanographic data (AVISO) in the offshore region are combined with coastal tide gauge time series of SSH to improve estimation in that gap along the west coast of the United States in the northern California Current System between 40° and 45°N and 123.8° and 126°W. To assess the increase in skill provided by this procedure, the geostrophic alongshore currents, calculated from the new SSH fields in the gap region, are compared to three in situ, nearshore current measurements, resulting in correlation coefficients of 0.73-0.83 and standard deviations of the differences of 11.6-12.6 cm/s, substantially improved from the AVISO-only results. When the Ekman current components are estimated and added to the geostrophic currents, comparisons to the 10 m deep acoustic Doppler current profiler velocities are only slightly improved. The Ekman components make a more significant contribution when compared to HF radar surface current measurements, providing correlations of 0.94 and standard deviations of the differences of 6.4-9.5 cm/s. These results represent a dramatic improvement in the quality of the SSH fields and estimated alongshore currents when additional, realistic SSH data from the coastal region are added. Here we use coastal tide gauges to provide the additional SSH data but also discuss more general approaches for altimeter SSH retrievals in coastal regions where tide gauge data are not available. Copyright 2008 by the American Geophysical Union. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_21699291_v113_n11_p_Saraceno
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Ocean currents
Oceanography
Tide gages
Time series analysis
coastal current
nearshore dynamics
satellite altimetry
satellite data
sea surface height
tide gauge
spellingShingle Ocean currents
Oceanography
Tide gages
Time series analysis
coastal current
nearshore dynamics
satellite altimetry
satellite data
sea surface height
tide gauge
Saraceno, M.
Strub, P.T.
Kosro, P.M.
Estimates of sea surface height and near-surface alongshore coastal currents from combinations of altimeters and tide gauges
topic_facet Ocean currents
Oceanography
Tide gages
Time series analysis
coastal current
nearshore dynamics
satellite altimetry
satellite data
sea surface height
tide gauge
description Present methods used to retrieve altimeter data do not provide reliable estimates of sea surface height (SSH) in the nearshore region, resulting in a measurement gap of 25-50 km next to the coast. In the present work, gridded SSH fields produced by Archiving, Validation, and Interpretation of Satellite Oceanographic data (AVISO) in the offshore region are combined with coastal tide gauge time series of SSH to improve estimation in that gap along the west coast of the United States in the northern California Current System between 40° and 45°N and 123.8° and 126°W. To assess the increase in skill provided by this procedure, the geostrophic alongshore currents, calculated from the new SSH fields in the gap region, are compared to three in situ, nearshore current measurements, resulting in correlation coefficients of 0.73-0.83 and standard deviations of the differences of 11.6-12.6 cm/s, substantially improved from the AVISO-only results. When the Ekman current components are estimated and added to the geostrophic currents, comparisons to the 10 m deep acoustic Doppler current profiler velocities are only slightly improved. The Ekman components make a more significant contribution when compared to HF radar surface current measurements, providing correlations of 0.94 and standard deviations of the differences of 6.4-9.5 cm/s. These results represent a dramatic improvement in the quality of the SSH fields and estimated alongshore currents when additional, realistic SSH data from the coastal region are added. Here we use coastal tide gauges to provide the additional SSH data but also discuss more general approaches for altimeter SSH retrievals in coastal regions where tide gauge data are not available. Copyright 2008 by the American Geophysical Union.
format JOUR
author Saraceno, M.
Strub, P.T.
Kosro, P.M.
author_facet Saraceno, M.
Strub, P.T.
Kosro, P.M.
author_sort Saraceno, M.
title Estimates of sea surface height and near-surface alongshore coastal currents from combinations of altimeters and tide gauges
title_short Estimates of sea surface height and near-surface alongshore coastal currents from combinations of altimeters and tide gauges
title_full Estimates of sea surface height and near-surface alongshore coastal currents from combinations of altimeters and tide gauges
title_fullStr Estimates of sea surface height and near-surface alongshore coastal currents from combinations of altimeters and tide gauges
title_full_unstemmed Estimates of sea surface height and near-surface alongshore coastal currents from combinations of altimeters and tide gauges
title_sort estimates of sea surface height and near-surface alongshore coastal currents from combinations of altimeters and tide gauges
url http://hdl.handle.net/20.500.12110/paper_21699291_v113_n11_p_Saraceno
work_keys_str_mv AT saracenom estimatesofseasurfaceheightandnearsurfacealongshorecoastalcurrentsfromcombinationsofaltimetersandtidegauges
AT strubpt estimatesofseasurfaceheightandnearsurfacealongshorecoastalcurrentsfromcombinationsofaltimetersandtidegauges
AT kosropm estimatesofseasurfaceheightandnearsurfacealongshorecoastalcurrentsfromcombinationsofaltimetersandtidegauges
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