JPL Oceanographer Watches Seas Rise Around the World from Pasadena Post

 

From the offices of the Jet Propulsion Laboratory in Pasadena, NASA scientists are using satellites to watch how quickly sea level is rising because of an accelerated phase of ice melting from glaciers on Greenland and the West Antarctic ice sheet.

Their work is part of an “intensive research effort” into the problem of rising seas brought on by global warming, the agency announced this week.

Part of this team is Josh K. Willis, an oceanographer and climate scientist at JPL, who is the project scientist for Jason-3, the fourth mission in a series of U.S.-European satellite missions that measure the height of the ocean surface.

Willis holds a Ph.D. in Oceanography from the University of California San Diego and has been a scientist with JPL since 2006.

In a new informative video made by JPL, Willis explains the causes of sea level rise and how sea level has changed over the last two decades as observed by the Jason series of satellite missions. Willis has been deeply involved in the Jason 1 and Jason 2 missions since these two earlier missions launched in 2001 and 2008.

“Hundreds of millions of people around the world live on coastlines that can be threatened by rising seas,” Willis says in the video. He then presents animation to show how sea levels have changed over the last 23 years.

“Globally see levels have gone up by about 6 cm during that time. But it doesn’t happen all at the same speed everywhere. Some places rising faster than others and some places or even falling.”

NASA on Wednesday released new visualization showing massive ice loss from Greenland since the year 2004 totaling 2,500 gigatons (a gigaton is a billion metric tons), or an average of 303 gigatons yearly for the past decade.

Since it takes 360 gigatons to raise sea level by a millimeter, that would suggest Greenland has done this about eight times over just in the last 10 years or so.

In 2013, scientists had a consensus that sea levels would rise between 30 and 90 centimeters, about one to three feet, by the end of the century. Now, with even more data to work with, researchers suggest that the rise is more likely to be at the higher end of that range.

Willis works with data compiled from 23 years of research using satellites such as the TOPEX/Poseidon mission in 1992 and continued through Jason 1 and Jason 2 where he was deputy project scientist for both. He says that while some regions have seen a decrease, the majority of the globe is experiencing sea level rise. He warns residents on the west coast of the U.S. not to get comfortable.

“Sea level along the west coast has actually fallen over the past 20 years because long-term natural cycles there are hiding the impact of global warming,” Willis says in a separate JPL release. “However, there are signs this pattern is changing. We can expect accelerated rates of sea level rise along this coast over the next decade as the region recovers from its temporary sea level ‘deficit.’”

The Jason 3 mission, delayed due to the recent Space X Falcon 9 mishap, will carry a radar altimeter as its primary instrument. The altimeter will measure sea- level variations over the global ocean with very high accuracy.

Willis’ team at JPL and other scientists will be using the continual, long-term reliable data of changes in ocean topography to be generated by Jason 3 for further scientific study on how these changes could impact human society.