KMSP - A study released by NASA says that Antarctica is actually increasing in overall size, adding yearly snow to parts of the continent that outweigh the loss of melting ice sheets. This new study is big news because it directly challenges the study of many others, including the Intergovernmental Panel on Climate Change’s (IPCC) report in 2013 which stated that Antarctica is losing land ice.
Scientists at NASA calculated how much the ice sheet has been growing or shrinking from the changes in surface height that are measured by satellite altimeters. In locations where the amount of new snowfall accumulating on an ice sheet is not equal to the ice flow downward and outward to the ocean and/or melting, the surface height changes and the ice-sheet mass grows or shrinks.
This research concluded that Antarctica showed a net gain of 112 billion tons of ice a year on average from 1992 to 2001 and then slowed to 82 billion tons of ice per year on average between 2003 and 2008.
The image below shows the continent broken into sections of study. The colors indicate which locations saw an increase or a decrease in altimeter height from satellite data.
Map showing the rates of mass changes from ICESat 2003-2008 over Antarctica. Sums are for all of Antarctica: East Antarctica (EA, 2-17); interior West Antarctica (WA2, 1, 18, 19, and 23); coastal West Antarctica (WA1, 20-21); and the Antarctic Peninsula (24-27). A gigaton (Gt) corresponds to a billion metric tons, or 1.1 billion U.S. tons.
Credits: Jay Zwally/ Journal of Glaciology
NASA’s study concluded a net gain of ice on Antarctica which means that the continent is NOT contributing to sea level rise, but is taking .23 millimeters away from seas every year. But there is a problem. The IPCC study released in 2013 concluded that .27 millimeters of sea level rise per year can be attributed to Antarctica. So if this isn’t the case, as NASA’s recent study suggests, then where is this extra .27 millimeters of rise coming from? Or is it even there to begin with? These are all questions that cannot be answered, but need to be. Therefore NASA is developing a successor to the program responsible for this new study called ICESat-2, which will launch in 2018. (ICESat is the original satellite) This new satellite will have a much higher resolution and hopefully give more accurate readings to altimeter changes on the continent.
The one thing research continues to prove is how difficult it is to measure overall climate change.