Validation of ESA CCI Sea Level Products Through Sea Level Budget Studies
Cazenave, Anny1; Dieng, Habib Boubacar2; Henry, Olivier2; Meyssignac, Benoit2; Stammer, Detlef3; von Schuckmann, Karina4; Ablain, Michael5; Larnicol, Gilles5; Benveniste, Jerome6; Faugère, Yannice5
1LEGOS_OMP, FRANCE; 2LEGOS, FRANCE; 3University of Hamburg, GERMANY; 4IFREMER, FRANCE; 5CLS, FRANCE; 6ESA/ESRIN, ITALY
Sea level responds to changes in the climate system on a large number of spatial and temporal scales. All components of the climate system (oceans, atmosphere, crysosphere, hydrosphere and solid Earth) and their mutual interactions produce sea level changes, in particular on interannual to multidecadal time scales. This is why modeling sea level rise and spatio-temporal sea level variability, and projecting future changes are considered as one of the most challenging problems in current climate research. For the last two decades, satellite altimetry shows that sea level has been rising at a sustained rate of about 3 mm/yr, at the upper end of process-based IPCC climate projections. Thus accurately measuring sea level and associated contributions (ocean warming, land ice melt, land water storage changes, etc.) using different space-based and in situ observing systems is a major objective that should help validating climate models used to project future changes. This is one of the goals of the ESA 'Climate Change Initiative –CCI-' project. In addition to improving sea level data from multi-missions satellite altimetry and producing long, accurate sea level time series at global and regional scales, it is also essential to perform independent validation of such data sets, in particular through sea level budget studies. Here we present most updated results of the sea level contributions (ocean thermal expansion, glacier and ice sheet mass balance, land water storage change, etc.) over the altimetry operating period (with focus on the last decade), using data from different observing and modeling systems (Argo, GRACE space gravimetry, ocean models and reanalyses, etc.) and compare their sum with products released by the ESA CCI ‘sea level’ project.