Blog Archive

Saturday, July 27, 2013

Arctic sea ice extent: 1920-1939 vs 2012

More on northern sea ice

A popular internet meme runs something like “melt was similar back in…”, usually referring to some arbitrary period in the 1920s or 1930s. Well, unsurprisingly, there really are quite good records from then, and, unsurprisingly, they show nothing remotely like current ice conditions:
The animation is drawn from the Danish Meteorological Institute’s sea ice maps for August in each year from 1920 to 1939.  The red marks show actual records of ice conditions and the white area is the inferred ice extent. The last image is the US National Snow and Ice Data Center’s satellite-derived sea ice concentration image for August 2012.
There’s also the historical sea ice extent compilation by Walsh and Chapman at the US National Center for Atmospheric Research / University of Illinois (as plotted at Cryosphere Today):
History of seasonal sea ice 1900-2010, NOAA
Again, ever considered the possibility you’ve been lied to?

No comments: