Measurements of Arctic sea ice at the end of this summer are the second lowest since modern record-keeping began in the 1970s, according to newly released preliminary findings.
According to NASA and the National Snow and Ice Data Center (NSIDC), Arctic sea level extent (the area of ocean covered by ice) is tied with 2007 and 2016 for second lowest, just behind the record minimum set in 2012. An analysis of satellite data shows the 2019 minimum extent measured 4.15 million square kilometers (1.6 million square miles) as of last week.
“This year’s minimum sea ice extent shows that there is no sign that the sea ice cover is rebounding,” said Claire Parkinson, a climate change senior scientist at NASA’s Goddard Space Flight Center, in a statement. “The long-term trend for Arctic sea ice extent has been definitively downward. But in recent years, the extent is low enough that weather conditions can either make that particular year’s extent into a new record low or keep it within the group of the lowest.”
Ice floating on top of the Arctic Ocean and its surrounding seas expands and thickens during the fall and winter and thins during the spring and summer, but in past decades, increasing temperatures have resulted in less sea ice throughout the year with rapid reductions observed at the end of the summer. Researchers say 2019 was an “interesting melt season” as we saw a rapid loss in July that slowed considerably up until the middle of August. Even so, August was at a record low for that time of year.
”But unlike 2012, the year with the lowest ice extent on record, which experienced a powerful August cyclone that smashed the ice cover and accelerated its decline, the 2019 melt season didn’t see any extreme weather events,” said Walt Meier, a sea ice researcher at NSIDC.
Even though the Arctic saw warmer than usual temperatures – an average of 4 to 5°C (7 to 9°F) above normal – sea ice extent was not significantly impacted by the severe Arctic wildfire season, record high temperatures or even the European heatwave.
“By the time the Siberian fires kicked into high gear in late July, the Sun was already getting low in the Arctic, so the effect of the soot from the fires darkening the sea ice surface wasn’t that large,” explained Meier. “As for the European heatwave, it definitely affected land ice loss in Greenland and also caused a spike in melt along Greenland’s east coast, but that’s an area where sea ice is being transported down the coast and melting fairly quickly anyway.”
NSIDC is quick to note that this is only a preliminary announcement and “changing winds or late-season melt could still reduce the Arctic ice extent." The agency will release a full analysis of the Arctic melt season early next month.