2014 Release 4 (2014-05-23):
- Added Jason-2/OSTM GDR cycles 208-209.
Instrument Drift Monitoring
To cite these plots or data, please use: Estimating Mean Sea Level Change from the TOPEX and Jason Altimeter Missions." Marine Geodesy 33, no. 1 supp 1 (2010): 435."
The Multivariate ENSO Index (MEI) is the unrotated, first principal component of six observables measured over the tropical Pacific (see NOAA ESRL MEI, Wolter & Timlin, 1993,1998). To compare the global mean sea level to the MEI time series, we removed the mean, linear trend, and seasonal signals from the 60-day smoothed global mean sea level estimates and normalized each time series by its standard deviation. The normalized values plotted above show a strong correlation between the global mean sea level and the MEI, with the global mean sea level often lagging changes in the MEI.
In this previous blog post, we incorrectly stated that Jason-2 had switched to the side B altimeter. In fact, only the processing chain (also known as the Platform Module) had switched to side B hardware. The actual altimeter instrument is still on side A.
As our FAQ states, we release new GMSL estimates as the Jason-2 GDR products are produced upstream by the French processing center AVISO. Cycles 170-172 were released by AVISO on May 9-10, and we released 2013_rel4 of our GMSL time series on May 15. Jason-2 did have two recent safe-hold periods during cycles 174 and 175, and these cycles will have impacted data. After the second safe-hold, Jason-2 automatically switched to its redundnat Platform Module-B. The operations team decided to leave Jason-2 operating on Platform Module-B, and no adverse effects have yet been noted to the science data.
The U.S. Senate Committee on Energy and Natural Resources had a hearing April 19, 2012 on the Impacts of Rising Sea Levels on Domestic Infrastructures. NASA Chief Scientist, Dr. Waleed Abdalati, gave testimony that included our release 2012_rel1 global mean sea level time series. More here.