Assessing satellite era global mean sea level change using tide gauges and estimates of land motion

Christopher Watson (University of Tasmania, Australia)


Benoit Legresy (CSIRO Oceans and Atmosphere Flagship, Australia); John Church (CSIRO Oceans and Atmosphere Flagship, Australia); Matt King (University of Tasmania, Australia); Alvaro Santamaría-Gómez (University of Tasmania, Australia)

Event: 2015 Ocean Surface Topography Science Team Meeting

Session: Science I: Mean sea level monitoring: how to reconcile altimetry, tide gauges, land motion and other in situ observations?

Presentation type: Type Oral

The satellite era sea level record is comprised of data from the TOPEX/Poseidon, Jason-1 and OSTM/Jason-2 missions, and is now approaching 23 years in duration. The accuracy of the record is dependent on the determination of any inter- and intra-mission biases, as well as the stability of these biases over time. Recent work published by our group suggests that these biases were significantly different to zero over the early part of the TOPEX record, having the effect of lowering the estimated rate of sea level rise 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 the tide gauge.

In this contribution, we provide updated results from our method and present further sensitivity tests to assess the performance of the technique. We extend our analysis in time for Jason-2 mission, and provide results for the candidate RGDR data for the TOPEX mission. We investigate strategies for minimising residual noise between the offshore altimeter comparison point and the coastal tide gauge sites, as well as assess the influence of applying the new ULR6 GPS based estimates of vertical land motion. We conclude with an assessment of the influence of the estimated bias drift corrections on the inferred rate of GMSL rise and its variation over the ~23 year record.

Oral presentation show times:

RoomStart DateEnd Date
Grand Ballroom 2 Tue, Oct 20 2015,14:45 Tue, Oct 20 2015,15:00
Christopher Watson
University of Tasmania