CoAuthors

Amanda Plagge (NOAA/GST, USA)

As Jason-3 and Sentinel-3 missions approach nearly two years on orbit, system drifts in global mean sea level can be determined via the global tide gauge network with uncertainties approaching 1 mm/year. Here we extend previously presented work comparing the effect of vertical land motion (VLM) at tide gauges on derived drift for the combined TOPEX/Jason-1/Jason-2/Jason-3 dataset. We also examine the drift in Sentinel-3A using comparisons with the gauges by making comparisons for each half cycle (13.5 days). Since the SRAL altimeter on Sentinel-3A is the first to operate in high-rate/delay-Doppler mode globally, comparisons with tide gauges provide an opportunity to better understand the source of errors in altimeter minus tide gauge residuals. We discuss our expectations for the monitoring the system drift in Jason-CS/Sentinel-CS missions, which have a goal of monitoring the change of global mean sea level to within a 1 mm over a year.