CoAuthors

Legresy Benoit (CSIRO, Australia); Church John (CSIRO, Australia); King Matt (University of Tasmania, Australia); Alvaro Santamaría-Gómez (Université de La Rochelle / CNRS, France)

The time series of global mean sea level (GMSL) derived from satellite altimetry is a seminal climate data record that describes one of the most robust manifestations of climate change. The accuracy of the record is dependent in-part on the determination of any inter- and intra-mission biases, as well as the stability of these biases over time. Our work published in 2015 suggested that biases in the early part of the TOPEX record were significantly different to zero, having the effect of lowering the estimated trend in GMSL over the full record from +3.2 mm/yr to between +2.6 to +2.9 ± 0.4 mm/yr, depending on the choice of land motion applied at tide gauge sites used in the estimation of bias drifts.

In this contribution we present an update of our solution with an emphasis on providing results for the TOPEX reanalysis dataset expected to be released prior to the OSTST meeting. We discuss strategies for minimising residual noise between the tide gauge and offshore comparison point, as well as investigating the impact of recently released GPS-based estimates for vertical land motion. We update our results for Jason-2 and present an early perspective from Jason-3.