Abstract's details
Improvements of Sentinel-3A altimetry data in the retrieval of sea level variability in the coastal region of the European Seas
CoAuthors
Event: 2019 Ocean Surface Topography Science Team Meeting
Session: Science III: Mesoscale and sub-mesoscale oceanography
Presentation type: Type Poster
Contribution: not provided
Abstract:
Altimeter missions have been providing accurate measurements of sea surface height (SSH) for the last 25 years. The quality assessment of altimetry data can be conducted by analysing their internal consistency and the cross-comparison between all missions. Moreover, in-situ measurements are also used as an external, independent reference.
In this work, we assess Sea Level Thematic Centre (SL-TAC) operational products in the European Seas using in-situ tide gauges from the Copernicus Marine Environment Monitoring Service (CMEMS) catalogue. Namely, we conduct an inter-comparison of delayed mode along-track sea level anomaly (SLA) from Sentinel-3A and Jason-3 satellite missions with SSH provided by in-situ tide gauges located in the European coasts of the North Atlantic Ocean, and in the Mediterranean Sea.
The processing of the tide gauge data includes corrections of (i) oceanic tidal effects by filtering high frequency diurnal and semidiurnal tides, (ii) long-period tide waves by using an algorithm based on well-balanced tide tables, (iii) atmospheric effects by subtracting the high frequency dynamical atmospheric correction, and (iv) vertical land movements associated to GIA. The comparison consists in co-locating altimetry and tide-gauge data. The method is based on a criterion of maximal correlation between tide gauge time series and altimeter L3 products. Then, statistics of sea level differences (correlation coefficient, root mean square error, variance) are computed. Results show a better performance of Sentinel-3A time series with respect to Jason-3 data in the coastal region of Europe. Similar results are obtained for the different sub-regions investigated.
In this work, we assess Sea Level Thematic Centre (SL-TAC) operational products in the European Seas using in-situ tide gauges from the Copernicus Marine Environment Monitoring Service (CMEMS) catalogue. Namely, we conduct an inter-comparison of delayed mode along-track sea level anomaly (SLA) from Sentinel-3A and Jason-3 satellite missions with SSH provided by in-situ tide gauges located in the European coasts of the North Atlantic Ocean, and in the Mediterranean Sea.
The processing of the tide gauge data includes corrections of (i) oceanic tidal effects by filtering high frequency diurnal and semidiurnal tides, (ii) long-period tide waves by using an algorithm based on well-balanced tide tables, (iii) atmospheric effects by subtracting the high frequency dynamical atmospheric correction, and (iv) vertical land movements associated to GIA. The comparison consists in co-locating altimetry and tide-gauge data. The method is based on a criterion of maximal correlation between tide gauge time series and altimeter L3 products. Then, statistics of sea level differences (correlation coefficient, root mean square error, variance) are computed. Results show a better performance of Sentinel-3A time series with respect to Jason-3 data in the coastal region of Europe. Similar results are obtained for the different sub-regions investigated.