Abstract's details
Validation of the latest Sentinel-3A/B surface topography baseline collection BC_005 over ocean
CoAuthors
Event: 2023 Ocean Surface Topography Science Team Meeting
Session: Regional and Global CAL/VAL for Assembling a Climate Data Record
Presentation type: Type Oral
Contribution: PDF file
Abstract:
Over the oceans, the Sentinel-3 (S-3) missions provide, among other variables, regular observations of sea surface elevation, significant wave height and wind speed. These represent key variables for monitoring global and regional sea level rise as well as improving our understanding of surface ocean dynamics. Goal of the EUMETSAT project “Copernicus Altimetry Service for the Sentinel-3 mission” (COPAS) is to monitor the S-3 observations over the ocean to ensure excellent overall performances. The COPAS activities include the validation of the ground processing and final products, the assessment of the long-term mission stability and the support for the continuous improvement of the S-3 STM performance.
In two steps, on 7th July 2022 and on 9th March 2023, a new reprocessing baseline (baseline collection 005, hereafter BC_005) has recently become operational, providing major evolutions in Sea Level, Wind and Waves and an overall increased quality of the observations. A full reprocessing campaign based on the new baseline collection has been completed this year, assuring homogeneous S3A/B observations for the whole duration of both missions. BC_005 brings several relevant evolutions and anomaly fixes to the S-3 altimetry marine products. The most important evolutions are new Sea State Bias correction, new GPD+ tropospheric correction, correction of USO reading and Range Walk correction to SAR mode. The latter two are expected to provide key improvements on the long-term stability of the S-3 sea level record.
Here, we provide an overview of the latest assessment of Sentinel-3A and 3B BC_005 performance over the ocean with respect to the previous processing baseline and in-situ observations. The analysis focuses on various geophysical parameters such as topography, wind and waves. The new baseline mission performance is evaluated through mono-mission diagnostics (e.g. cross-over analysis) as well as comparison with other altimeters, models as well as tide-gauges and wave buoy observations. Dedicated diagnostics have been analysed to assess the performance over the polar oceans. Particular attention is also reserved to the long-term analysis of the S-3 mission performances. In particular, we showed that the corrections and new algorithms introduced with the BC_005 effectively rectified (as expected) the drifts in the global long-term trends of sea level anomaly.
In two steps, on 7th July 2022 and on 9th March 2023, a new reprocessing baseline (baseline collection 005, hereafter BC_005) has recently become operational, providing major evolutions in Sea Level, Wind and Waves and an overall increased quality of the observations. A full reprocessing campaign based on the new baseline collection has been completed this year, assuring homogeneous S3A/B observations for the whole duration of both missions. BC_005 brings several relevant evolutions and anomaly fixes to the S-3 altimetry marine products. The most important evolutions are new Sea State Bias correction, new GPD+ tropospheric correction, correction of USO reading and Range Walk correction to SAR mode. The latter two are expected to provide key improvements on the long-term stability of the S-3 sea level record.
Here, we provide an overview of the latest assessment of Sentinel-3A and 3B BC_005 performance over the ocean with respect to the previous processing baseline and in-situ observations. The analysis focuses on various geophysical parameters such as topography, wind and waves. The new baseline mission performance is evaluated through mono-mission diagnostics (e.g. cross-over analysis) as well as comparison with other altimeters, models as well as tide-gauges and wave buoy observations. Dedicated diagnostics have been analysed to assess the performance over the polar oceans. Particular attention is also reserved to the long-term analysis of the S-3 mission performances. In particular, we showed that the corrections and new algorithms introduced with the BC_005 effectively rectified (as expected) the drifts in the global long-term trends of sea level anomaly.
