Xu Yang (SGT Inc., USA); Gary Mitchum (University of South Florida, USA); Richard Ray (NASA GSFC, USA); Frank Lemoine (NASA GSFC, USA); Nikita Zelensky (SGT Inc., USA); Bryant Loomis (NASA GSFC, USA)

The determination of the rate of change of mean sea level has undeniable societal significance. The measurement of geocentric sea level change from satellite altimetry requires vigilant monitoring of the altimeter measurement system stability since the signal being measured is at the level of a few mm/yr. In this presentation we report inter-comparisons of current Jason-3 and coincident Sentinel-3A drift estimates based on sea surface height (SSH) differences with respect to a global tide gauge network. Jason-3/Sentinel-3A SSH and range correction crossover residual time series are evaluated to provide additional insight to Jason-3 stability interrogations. We provide an assessment of recent improvements to the accuracy of the 25-year sea surface height time series, describe continuing calibration/validation activities, and evaluate the subsequent impact on current global and regional mean sea level estimates.