Read here. The new technology that GRACE (Gravity Recovery and Climate Experiment) satellite measurements represent appears to have major biases and is error-prone. Unfortunately, climate scientists who advocate climate alarmism misuse the GRACE findings to support their views without stating the critical GRACE short-comings. (Update: new GRACE article from WUWT.)
"In an effort designed to provide some of that "detailed understanding" of GRACE's "errors and biases," Quinn and Ponte conducted what they describe as "a detailed analysis of processing and post-processing factors affecting GRACE estimates of ocean mass trends," by "comparing results from different data centers...".....The two researchers report that the mean ocean mass trends they calculated "vary quite dramatically depending on which GRACE product is used, which adjustments are applied, and how the data are processed.".....In light of the fact that Quinn and Ponte indicate that "over the last century, the rate of sea level rise has been only 1.7 ± 0.5 mm/year, based on tide gauge reconstructions (Church and White, 2006)," it seems a bit strange that one would ever question that result on the basis of a GRACE-derived assessment, with its many and potentially very large "errors and biases.".....Clearly, the GRACE approach to evaluating ocean mass and sea level trends still has a long way to go -- and must develop a long history of data acquisition -- before it can ever be considered a reliable means of providing assessments of ocean mass and sea level change"