Regional and global rates of ocean mass addition between 1996-2006 from a full depth sea level rise budget

Abstract:

Regional and global rates of Sea Level Rise (SLR) owing to mass addition are assessed through a full-depth SLR budget using full-depth in-situ ocean data and satellite altimetry centered between 1996–2006. These rates are compared to regional and global trends in ocean mass addition estimated directly using data from the Gravity Recovery and Climate Experiment (GRACE) from 2003–2013. Despite the two independent methods reflecting different time periods and spatial sampling coverage, they both capture the same large scale mass addition trend patterns of higher rates of mass addition in the North Pacific, South Atlantic, and the Indo-Atlantic Sector of the Southern Ocean, with smaller mass addition trends in the Indian, North Atlantic, South Pacific, and the Pacific Sector of the Southern Ocean. The global mean trend of ocean mass addition using both methods is 1.5 (±0.4) mm yr^-1, reflecting 1996–2006 for the residual method and 2003–2013 for the GRACE method. Furthermore, the residual method is used to evaluate the error introduced into the mass budget if the deep steric contributions below 700, 1000, 2000, 3000, and 4000 m are neglected revealing an error of 65%, 38%, 13%, 8% and 4% respectively. The two methods no longer agree within error bars when only the steric contribution shallower than 1000 m is considered.