NASA’s Image of the Day for April 5, 2016 shows the waters of the north Atlantic Ocean:
Earth’s north polar ice cap was smaller this past winter than at any time since measurements began to be obtained by satellite, breaking a record set only last year.
NASA and the National Snow and Ice Data Center announced March 28 that the maximum extent of ice during the season was reached on March 24 and that it covered 14.52 million square kilometers.
That beat last year’s mark of 14.54 million square kilometers and continued a stretch in which the 13 most ice-free winters in the Arctic have occurred in the past 13 years.
“It is likely that we’re going to keep seeing smaller wintertime maximums in the future because in addition to a warmer atmosphere, the ocean has also warmed up. That warmer ocean will not let the ice edge expand as far south as it used to,” Walt Meier, a sea ice scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said. “Although the maximum reach of the sea ice can vary a lot each year depending on winter weather conditions, we’re seeing a significant downward trend, and that’s ultimately related to the warming atmosphere and oceans.”
During the most recent winter season the Arctic experienced record high temperatures in December, January, and February. Air temperatures were as much as 10 degrees Fahrenheit higher than average at the edge of the ice pack, Meier said.
Warm air from the south was brought by winds to the Arctic, which also would have contributed to a lessened sea ice cover.
Less winter sea ice causes the air temperature over the Arctic ocean to increase because the unfrozen ocean waters are warmer than the overlaying air mass. As the ocean water evaporates, more water vapor accumulates in the atmosphere and that, in turn, causes clouds to form. Increased cloudiness causes an increase in surface warmth.
Satellite measurements of Arctic winter ice extent began in 1979.
Since that time the Arctic has lost nearly 1,606 square kilometers of winter sea ice. That is an area twice the size of Texas.
One of the Expedition 36 crew members aboard the International Space Station used a 50mm lens to record this image of a large mass of storm clouds over the Atlantic Ocean near Brazil and the Equator on July 4, 2013. A Russian spacecraft, docked to the orbiting outpost, partially covers a small patch of sunglint on the ocean waters in a break in the clouds. Photo courtesy NASA.