Estimating Mean Sea Level Change from the TOPEX and Jason Altimeter Missions

The Jason-2 satellite altimeter mission was launched in June 2008, extending the record of precision sea level measurements that was initiated with the launch of TOPEX/Poseidon in 1992 and continued with the launch of Jason-1 in December 2001. We have used the measurements from these three missions to construct a seamless record of global mean sea level change from 1993 to the present. We present the results of our calibration activities, including data comparisons during the tandem period of the missions, during which we solve for biases between the missions, as well as comparisons to independent tide gauge sea level measurements. When the entire record is assembled, the average rate of sea level rise from 1993-2009 is 3.4 +/- 0.4 mm/year. There is considerable interannual variation due to ENSO-related processes, which include the period of lower sea level rise over the last three years of the time series during the recent La Nina event.