Level-3 CNES ensemble solution, assessment with lake altimetry

We propose a status update on the Level-3 (L3) solution with uncertainties produced by the CNES. The L3 solution is designed to analyze the global water cycle consistently with the conservation of mass. In particular, the L3 solution has been used to estimate glacier mass loss in Arctic regions, Greenland and Antarctica, as well as water mass change in these areas. The ocean mass product and its uncertainty is designed in a consistent way with satellite altimetry products to estimate the Earth’s energy imbalance.

We assess the quality of the solution and its uncertainties with external independent datasets from satellite altimetry observations and in-situ measurements. Comparisons of the mass estimation on large lakes provide insights into glacial isostatic adjustment, showing that the ICE-6G_D model aligns better with the observed trends in North America water volume from altimetry than the mean value of Caron 2018 model. We observe that for most of the lakes the seasonal maximum of the surface water takes place 1 to 2 months before the whole land water observed by GRACE.