Friday, May 14, 2010

NASA scientist Thorsten Markus: Earth thinning on top

Thorsten Markus, of NASA’s Goddard Space Flight Center, has been using a NASA satellite – called ICESat – to track the thickness of sea ice around Earth’s poles. He said the thick, multi-year ice is getting thinner.

"We are able, for the first time really, to measure the sea ice thickness at large scales. Previously, the only means, really, was to drill holes through the ice. Results from ICESat have shown that just since 2003, when ICESat was launched, the sea ice thickness has decreased by over two feet. The thick, multi-year ice has decreased by over 40 percent during that time...Sea ice is white and it reflects most of the sunlight back into space, in drastic contrast to the dark ocean. Therefore, changes in the sea ice cover have a significant effect on the global energy balance."

In other words, less sea ice could cause more warming. The satellite Markus uses – ICESat – was retired in early 2010 after 7 years collecting data in Earth orbit. ICESat-II will launch in 2015. Until then, Dr. Markus will use what’s called Ice Bridge – aircraft in flight over the polar regions – to measure and track changes. In addition to the sunlight it reflects, Dr. Markus said that as salt water freezes to form sea ice, at a large scale it impacts weather and climate.

Thorsten Markus joined NASA Goddard Space Flight Center first as a post-doc and then permanently as a research scientist. His research interests include remote sensing of the polar regions and the use of remote sensing data to study polar processes.


  1. I am confused. I keep seeing statements that suggest that the melting of ice increases air temp.I believe this is just the opposite of what actually happens. When ice melts heat is aborbed
    from the atmosphere.

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  3. Sorry -- those links got messed up. For a better answer than I can give, look here:
    or here: