Basin Scale Mass Variations in the Atlantic Ocean
Saskia Esselborn(1) , Tilo Schöne(1) , Silvia Becker(1) , and Roland Schmidt(1)
Variations in oceanic mass are on the one hand related to changes in ocean dynamics and on the other hand to changes in the global freshwater cycle. Until recently it has not been feasible to derive this quantity on large spatial scales from measurements. Nowadays it can be obtained by the reduction of steric from total sea level changes as well as by the analysis of temporal changes in the gravity field.
In this study space-based altimeter (ERS-2, TOPEX and Jason-1) and in-situ Argo data (CORIOLIS project) are combined to derive monthly mass related sea level variations in the Atlantic Ocean for the period 2000 to 2005. From 2002 onward the global mass redistributions have been monitored by the GRACE satellites. An independent estimate of monthly mass variations in the Atlantic Ocean is generated from the latest time series of monthly GRACE-only gravity models in the Atlantic Ocean processed at GFZ Potsdam. After adequate spatial filtering the two data sets are compared and the advantages and disadvantages of the two
approaches are identified. Typical temporal and spatial scales of these data and the relationship between steric and mass related sea level variations are further investigated for the Atlantic Ocean.