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According to NASA, On March 24, Arctic sea ice extent peaked at 5.607 million square miles (14.52 million square kilometers), a new record low winter maximum extent in the satellite record that started in 1979. It is just smaller than the previous record low maximum extent of 5.612 million square miles (14.54 million square kilometers) that occurred last year. The 13 smallest maximum extents on the satellite record have happened in the last 13 years. Every year, the cap of frozen sea water floating at the top of the Arctic Ocean and its neighboring seas loses ice in the spring and summer and gains ice in the fall and winter, reaching its maximum amount of ice sometime between February and April.
The new record low is attributed to the record high temperatures in December, January and February that were experienced around the globe and in the Arctic. Around the edges of the ice pack where the sea ice is thin, temperatures were as high as 10 degrees Fahrenheit above average, which halted ice development in its tracks. The wind patterns in the Arctic throughout January and February were also unfavorable to ice development because they brought warm air from the south and prevented expansion of the ice cover. Warming ocean temperatures was the major factor that prevented ice development throughout the 2015-2016 winter.
“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. 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,” said Walt Meier, a sea ice scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
Since 1979, a persistent downward trend has led to the loss of 620,000 square miles of winter sea ice cover, an area more than twice the size of Texas. Despite the fact that this winter lead to a record low maximum extent of ice, that doesn’t mean that this summer will also reach a record low. Summer weather conditions have a bigger impact than the extent of the winter maximum in the outcome of each year’s melt season; warm temperatures and summer storms make the ice melt fast, while if a summer is cool, the melt slows down. Arctic sea ice plays an important role in maintaining Earth’s temperature, its bright white surface reflects solar energy that the ocean would otherwise absorb. This sea allows many animals to survive in a climate that maintains reasonable temperatures, so if a lot more sea ice melts, it will threaten the lives of many animals!
“In places where sea ice has been lost, those areas of open water will put more heat into the atmosphere because the air is much colder than unfrozen sea water. As winter sea ice disappears, areas of unusually warm air temperatures in the Arctic will expand. These are also areas of increased evaporation, and the resulting water vapor will contribute to increased cloudiness, which in winter, further warms the surface,” said Jennifer Francis, a climate scientist at Rutgers University in New Brunswick, New Jersey.
