Impact of Altimeter Data Processing on Sea Level Studies
This study addresses the impact of satellite altimetry data processing on sea levelstudies at regional scale, with emphasis on the influence of various geophysical correctionsand satellite orbit on the structure of the derived interannual signal and sea level trend. Thework focuses on the analysis o...
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| Format: | Article |
| Language: | English |
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MDPI AG
2006-03-01
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| Series: | Sensors |
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| Online Access: | http://www.mdpi.com/1424-8220/6/3/131/ |
| _version_ | 1828348947095093248 |
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| author | Clara Lázaro Susana Barbosa M. Joana Fernandes |
| author_facet | Clara Lázaro Susana Barbosa M. Joana Fernandes |
| author_sort | Clara Lázaro |
| collection | DOAJ |
| description | This study addresses the impact of satellite altimetry data processing on sea levelstudies at regional scale, with emphasis on the influence of various geophysical correctionsand satellite orbit on the structure of the derived interannual signal and sea level trend. Thework focuses on the analysis of TOPEX data for a period of over twelve years, for threeregions in the North Atlantic: Tropical (0o≤Æ≤25o), Sub-Tropical (25o≤Æ≤50o) and Sub-Arctic (50o≤Æ≤65o). For this analysis corrected sea level anomalies with respect to a meansea surface model have been derived from the GDR-Ms provided by AVISO by applyingvarious state-of-the-art models for the geophysical corrections. Results show that sea leveltrend determined from TOPEX altimetry is dependent on the adopted models for the majorgeophysical corrections. The main effects come from the sea state bias (SSB), and from theapplication or not of the inverse barometer (IB) correction. After an appropriate modellingof the TOPEX A/B bias, the two analysed SSB models induce small variations in sea leveltrend, from 0.0 to 0.2 mm/yr, with a small latitude dependence. The difference in sea leveltrend determined by a non IB-corrected series and an IB-corrected one has a strong regionaldependence with large differences in the shape of the interannual signals and in the derivedlinear trends. The use of two different drift models for the TOPEX Microwave Radiometer(TMR) has a small but non negligible effect on the North Atlantic sea level trend of about0.1 mm/yr. The interannual signals of sea level time series derived with the NASA and theCNES orbits respectively, show a small departure in the middle of the series, which has noimpact on the derived sea level trend. These results strike the need for a continuousimprovement in the modelling of the various effects that influence the altimetermeasurement. |
| first_indexed | 2024-04-14T01:02:25Z |
| format | Article |
| id | doaj.art-6d2940ec8a3448b4a6343bbdccb389e5 |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-04-14T01:02:25Z |
| publishDate | 2006-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-6d2940ec8a3448b4a6343bbdccb389e52022-12-22T02:21:21ZengMDPI AGSensors1424-82202006-03-016313116310.3390/s6030131Impact of Altimeter Data Processing on Sea Level StudiesClara LázaroSusana BarbosaM. Joana FernandesThis study addresses the impact of satellite altimetry data processing on sea levelstudies at regional scale, with emphasis on the influence of various geophysical correctionsand satellite orbit on the structure of the derived interannual signal and sea level trend. Thework focuses on the analysis of TOPEX data for a period of over twelve years, for threeregions in the North Atlantic: Tropical (0o≤Æ≤25o), Sub-Tropical (25o≤Æ≤50o) and Sub-Arctic (50o≤Æ≤65o). For this analysis corrected sea level anomalies with respect to a meansea surface model have been derived from the GDR-Ms provided by AVISO by applyingvarious state-of-the-art models for the geophysical corrections. Results show that sea leveltrend determined from TOPEX altimetry is dependent on the adopted models for the majorgeophysical corrections. The main effects come from the sea state bias (SSB), and from theapplication or not of the inverse barometer (IB) correction. After an appropriate modellingof the TOPEX A/B bias, the two analysed SSB models induce small variations in sea leveltrend, from 0.0 to 0.2 mm/yr, with a small latitude dependence. The difference in sea leveltrend determined by a non IB-corrected series and an IB-corrected one has a strong regionaldependence with large differences in the shape of the interannual signals and in the derivedlinear trends. The use of two different drift models for the TOPEX Microwave Radiometer(TMR) has a small but non negligible effect on the North Atlantic sea level trend of about0.1 mm/yr. The interannual signals of sea level time series derived with the NASA and theCNES orbits respectively, show a small departure in the middle of the series, which has noimpact on the derived sea level trend. These results strike the need for a continuousimprovement in the modelling of the various effects that influence the altimetermeasurement.http://www.mdpi.com/1424-8220/6/3/131/Satellite AltimetrySea Level ChangeGeophysical Corrections |
| spellingShingle | Clara Lázaro Susana Barbosa M. Joana Fernandes Impact of Altimeter Data Processing on Sea Level Studies Sensors Satellite Altimetry Sea Level Change Geophysical Corrections |
| title | Impact of Altimeter Data Processing on Sea Level Studies |
| title_full | Impact of Altimeter Data Processing on Sea Level Studies |
| title_fullStr | Impact of Altimeter Data Processing on Sea Level Studies |
| title_full_unstemmed | Impact of Altimeter Data Processing on Sea Level Studies |
| title_short | Impact of Altimeter Data Processing on Sea Level Studies |
| title_sort | impact of altimeter data processing on sea level studies |
| topic | Satellite Altimetry Sea Level Change Geophysical Corrections |
| url | http://www.mdpi.com/1424-8220/6/3/131/ |
| work_keys_str_mv | AT claralaƒazaro impactofaltimeterdataprocessingonsealevelstudies AT susanabarbosa impactofaltimeterdataprocessingonsealevelstudies AT mjoanafernandes impactofaltimeterdataprocessingonsealevelstudies |