Something strange is happening in the Arctic. For two days in November, the Arctic sea ice did not behave as expected.
Arctic sea ice increases in winter and shrinks in summer, and scientists keep a close eye on how much it increases or shrinks by. That’s because Arctic sea ice is a key indicator of how global warming is affecting the planet. This November, something happened that had everyone puzzled.
Sea ice extent reaches record lows
We already know that 2016 is shaping up to be the hottest year on record. At the same time, the Arctic sea ice extent – the amount of sea that is turning to ice – is showing record lows.
The next day, the gap widened further, with 8.625 million square kilometers in 2016 versus 9.632 million in 2012.
“Over the past few days, extent has actually decreased in the Arctic, and while I don’t think that such a short-term decline is unprecedented for this time of year, it is highly unusual, for November is a month when we normally see a quite rapid ice growth,” Mark Serreze, director of the National Snow and Ice Data Center told the Washington Post.
It’s because of higher-than-usual sea surface temperatures, and unusually high air temperatures.
This year the Arctic sea ice has retreated earlier than normal, meaning that the sea had longer to absorb the heat from the sun. As a result, at the start of the season when sea ice should be forming, the water was still too warm.
Air temperature also played a part. October’s air temperatures were unusually high over most of the Arctic Ocean for that time of year.