Area and thickness determines state of Arctic ice

William Atkins
Tuesday, 07 April 2009 18:20

Science - Climate

Thus, thick, winter ice has gone from 30 to 40% in the 1980s and 1990s to about 10% in the 2000s.

In other words, we have more thinner ice and less thicker ice than we did twenty five years ago.

In fact, NASA stated, “… this winter had the fifth lowest maximum ice extent on record. The six lowest maximum events since satellite monitoring began in 1979 have all occurred in the past six years (2004-2009).”

In other words, the total amount of area of ice has decreased dramatically over the past decade, as has the thickness of the ice.

With respect to area, scientists at the National Snow and Ice Data Center (NSIDC) Boulder, Colorado) found that the maximum area of sea ice for 2008-09 was 5.85 million square miles (15.15 square kilometers) and an average of 5.57 million square miles (14.43 square kilometers) between 1979 and 2000. The area decreased about 278,000 square miles (720 square kilometers) over this nearly three-decade time.

Walter Meier, from the NSIDC and UC, stated, "Ice extent is an important measure of the health of the Arctic, but it only gives us a two-dimensional view of the ice cover.”

Meier adds, “Thickness is important, especially in the winter, because it is the best overall indicator of the health of the ice cover. As the ice cover in the Arctic grows thinner, it grows more vulnerable to melting in the summer."

Dr. Kwok looks to the future with his statement, "With these new data on both the area and thickness of Arctic sea ice, we will be able to better understand the sensitivity and vulnerability of the ice cover to changes in climate.”

For more information about Arctic sea ice, visit Arctic Sea Ice News and Analysis: “Daily Image Update.”

A recent U.S. study (“September sea-ice cover in the Arctic Ocean projected to vanish by 2100”) shows that the Arctic Ocean could likely be free of summer sea ice before the end of the twenty-first century if the world continues to emit future greenhouse-gases at a “medium” rate.