It’s finally here! Yesterday, scientists from the
National Snow and Ice Data Center announcedthe ultimate sign of spring: Arctic
sea ice reached its winter peak on March 21, 2014, and the annual melt season
is underway.
This winter’s maximum sea ice extent in the Arctic was
14.91 million square kilometers (5.76 million square miles), making it the
fifth smallest winter maximum since satellite records began in 1979.
Meanwhile, Southern Hemisphere sea ice reached its
annual low point on February 23, 2014. This year’s summer minimum extent was
3.54 million square km (1.37 million square mi), which was the fourth largest
in the satellite record.
Global warming due to rising atmospheric
concentrations of carbon dioxide and other greenhouse gases is having different
impacts on sea ice patterns in the Arctic versus the Antarctic. The Arctic is
experiencing declines in ice cover in nearly all areas and all seasons, with
especially large losses in summer.
In the Antarctic, sea ice trends are more variable.
Over the Southern Ocean as a whole, sea ice extent has increased by a small
amount on an annual basis, with decreases in some basins and increases in
others and changes in some seasons but not others.
For more on differences between our planet’s two “ends
of the Earth” see our Polar Oppositesfeature article.
Globes by Dan Pisut, based on data provided by the
National Snow and Ice Data and available from NOAA View.
Photo Credit:
NOAA View
NSIDC
NOAA Climate.gov
