Arctic ice reached its lowest peak level since 1978. (Credit: NASA)
Arctic ice reaches annual its peak area in February and March, and this year’s peak level was the lowest since 1978, according to an article in the New York Times. The ice-covered area will only get smaller throughout the rest of 2015.
Researchers have pinned this year’s unusually low peak level on irregularities in the jet stream, the relatively thin, fluctuating air current that tends to separate cold air regions from warm. This year’s jet stream went higher north than usual, making for an unusually warm North Pacific. The jet stream also headed further south than usual, causing unusual cold and snow in much of the continental U.S.
However, researchers note that the lowest ebb of Arctic ice, in September, actually has a greater effect on climate than the peak level of ice in February-March. The ice-free regions that emerge in September absorb more heat due to the dark ocean water. In other parts of the year, ice would be present, reflecting light and lowering temperatures instead.
Summer ice loss is felt to be more serious, as the trend for many years has been that the summer ice is not regained during winter peak ice season, leading to a concerning downward trend over many years.
Top image: Arctic ice reached its lowest peak level since 1978. (Credit: NASA)