Arctic Sea Ice at all-time low
What is surprising is that this new record comes a month early. The ice is still melting! The frozen layer of sea ice that covers much of the Arctic Ocean, including the North Pole, expands and contracts with the seasons in the Northern Hemisphere. In Winter, the ice cover grows dramatically, reaching a maximum extent in early Spring. In the warmer months, however, the over-extended ice cover retreats to cooler climes, reaching it's smallest extent in mid-September, as show by the solid black line in the chart below.
Arctic sea ice, unfortunately, is one of the major victims of global warming. On August 9th, 2007, a record low in the extent of Arctic sea ice was recorded (cyan line above), beating out the previous record low of 2005 (dashed green line above). This is not surprising in light of the Arctic's unfair share of climate change. What is surprising is that this new record comes a month early. The ice is still melting!
Below are two images comparing sea-ice concentrations (denser sea ice has fewer leads, or breaks in the ice, and is usually thicker) from the minimum extent in 1979 to the extent on August 9th.
The trend in Arctic sea ice has been dramatic, as illustrated in the following chart.
Finally, the map below shows the sea-ice extent in August (white) compared to the median Julie sea-ice extent (magenta line).
All of this is in the context of rapid climate change. One measure of global temperatures, produced by NASA GISS, was recently updated and, unlike other similar records, includes the Arctic. The figure follows.
