Error variance-covariance, trends, accelerations and uncertainties of regional mean sea level estimated from satellite altimetry

Date 2020-11-12
Temporal extent 1993 -2019
Author(s) Prandi PierreORCID1, Meyssignac BenoitORCID2, Ablain MichaëlORCID3, Spada GiorgioORCID4, Ribes AurélienORCID5
Affiliation(s) 1 : Collecte Localisation Satellites, Ramonville Saint-Agne, France
2 : CNES, LEGOS, Toulouse, France
3 : Magellium, Ramonville Saint-Agne, France
4 : Urbino University, DiSPeA, Urbino, Italy
5 : CNRM - Centre National de Recherche Météorologique, France
DOI 10.17882/74862
Publisher SEANOE
Keyword(s) satellite altimetry, error covariance, sea level, uncertainties
Abstract

Satellite altimetry missions provide a quasi-global synoptic view of sea level over more than 25 years. The satellite altimetry constellation is used to build sea level maps and regional sea level indicators such as trends and accelerations. Estimating realistic uncertainties on these quantities is crucial to address some current climate science questions such as climate change detection and attribution or regional sea level budget closure for example. Previous studies have estimated the uncertainty for the global mean sea level (GMSL), but no uncertainty information is available at regional scales.

In this study we estimate a regional satellite altimetry error budget and use it to derive maps of confidence intervals for local sea rise rates and accelerations. We analyze 27 years of satellite altimetry maps and derive the satellite altimetry error variance-covariance matrix at each grid point, prior to the estimation of confidence intervals on local trends and accelerations at the 90% confidence level using extended least squares estimators.

Over 1993–2019, we find that the average local sea level trend uncertainty is 0.83 mm.yr-1 with local values ranging from 0.78 to 1.22 mm.yr-1. For accelerations, uncertainties range from 0.057 to 0.12 mm.yr-2, with a mean value of 0.063 mm.yr-2.

 

Change history:


  • 2020/07/08: initial dataset submission over 1993-2018

  • 2020/10/21: 1993-2019 update and addition of error levels

Licence CC-BY
Acknowledgements We thank ESA and CNES for their support.
Data
File Size Format Processing Access Key
42 MB NC, NetCDF Processed data Access on demand 75264
1993-2019 data 47 MB NC, NetCDF Quality controlled data Open access 77853
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How to cite 

Prandi Pierre, Meyssignac Benoit, Ablain Michaël, Spada Giorgio, Ribes Aurélien (2020). Error variance-covariance, trends, accelerations and uncertainties of regional mean sea level estimated from satellite altimetry. SEANOE. https://doi.org/10.17882/74862