Dallas Masters's blog
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.
NASA mission takes stock of Earth's melting land ice - In the first comprehensive satellite study of its kind, a University of Colorado at Boulder-led team used NASA data to calculate how much Earth's melting land ice is adding to global sea level rise. [NASA Climate News]
Our colleagues at JPL have also been interested in how the global mean sea level is affected by the ENSO (i.e., El Niño and La Niña). They find that GRACE measurements helped to identify the distribution of abnormally high rainfall over land resulting from the recent strong La Niña. This temporary transfer of large volumes of water from the oceans to the land surfaces also helps explain the large drop in global mean sea level. But they also expect the global mean sea level to begin climbing again.
An Update from NASA's Sea Level Sentinels:
Like mercury in a thermometer, ocean waters expand as they warm. This, along with melting glaciers and ice sheets in Greenland and Antarctica, drives sea levels higher over the long term. For the past 18 years, the U.S./French Jason-1, Jason-2 and Topex/Poseidon spacecraft have been monitoring the gradual rise of the world's ocean in response to global warming.
While the rise of the global ocean has been remarkably steady for most of this time, every once in a while, sea level rise hits a speed bump. This past year, it's been more like a pothole: between last summer and this one, global sea level actually fell by about a quarter of an inch, or half a centimeter.
So what's up with the down seas, and what does it mean? Climate scientist Josh Willis of NASA's Jet Propulsion Laboratory, Pasadena, Calif., says you can blame it on the cycle of El Niño and La Niña in the Pacific. [Read more...]