The Arctic Ice Cap
The Arctic ice cap shrank so much that waves briefly lapped along two long-imagined Arctic shipping routes, the Northwest Passage over Canada and the Northern Sea Route over Russia. Complicating the picture, the striking Arctic change was as much a result of ice moving as melting.
A host of Arctic scientists say it is too soon to know if the global greenhouse effect has already tipped the system to a condition in which sea ice in summers will be routinely limited to a few clotted passageways in northern Canada.
As we move along with those pictures we can see the Arctic ice caps are melting but very fast. In 2005 the scenario was much worst.
All those pictures were taken on September 16th each year, which is right after the summer. Summer 2007 shows a record breaking loss of arctic sea ice. Experts attribute the changes to the interaction of wid. Weather, ice drift, ocean current and greenhouse gases. On September 16, 2007 summer sea ice extent was about 1.7 million square miles. High pressure over the Arctic and low pressure over Siberia funneled warm winds across the Arctic Ocean. The air pressure at sea level June to August 2007 was 1018millibars but before June it was 1006millibars. The air temperature also increased with air pressure. Warm air from northeastern Siberia brought heat to the region and pushed sea ice away from the coast and the average temperature raised 8°F. High pressure also helped create a broad patch of clear sky over the Arctic, allowing more sunlight to heat the ocean. The average cloud cover June- July 2007 was only 20%. Because open water reflects less sunlight and absorbs more heat than snow or ice. Heat absorbed this summer could slow the winter freeze. Trend in solar heating of the ocean 1979-2005 was 5% per year.
Over all, the floating ice dwindled to an extent unparalleled in a century or more, by several estimates. Experts say the ice retreat is likely to be even bigger next summer because this winter’s freeze is starting from such a huge ice deficit. Researcher, Wieslaw Maslowski of the Naval Postgraduate School in Monterey, Calif., projects a blue Arctic Ocean in summers by 2013.