Highlights of the Arctic Report Card:
- Average annual surface air temperature anomaly (+1.3°C) over land north of 60°N for October 2014-September 2015 was the highest in the observational record beginning in 1900; this represents a 2.9°C increase since the beginning of the 20th Century.
- Average air temperature anomalies in all seasons between October 2014 and September 2015 were generally positive throughout the Arctic, with extensive regions exceeding +3°C relative to a 1981-2010 baseline.
- Anomalously warm conditions from November 2014 through June 2015 in Alaska were caused by weather patterns that advected warm mid-latitude air northward from the northeast Pacific Ocean. Anomalously warm Arctic conditions during spring (April, May, June) 2015 across central Eurasia were also due to southerly winds.
- Strong connections between the Arctic and the mid-latitudes were also seen in late winter-early spring (February-April) 2015, when cold air advected south-eastward from the central Arctic resulted in major negative temperature anomalies over eastern North America.
- Melt area in 2015 exceeded more than half of the ice sheet on July 4th for the first time since the exceptional melt events of July 2012, and was above the 1981-2010 average on 54.3% of days (50 of 92 days).
- The length of the melt season was as much as 30-40 days longer than average in the western, northwestern and northeastern regions, but close to and below average elsewhere on the ice sheet.
“In general, air temperatures in all seasons were above average throughout the Arctic, with extensive regions exceeding 5.4 degrees Fahrenheit over the 1981-2010 baseline,” Richter-Menge told reporters at the American Geophysical Union conference in San Francisco.
The warmer air contributed to changes in the amount of Arctic sea ice, which peaked on Feb. 25 – 15 days earlier than average. This winter ice pack was the smallest on record since 1979.
In addition, only 3 percent of the ice cover in February and March 2015 was so-called “old ice,” which is older than four years. New, first-year ice made up 70 percent of the pack, the research showed. Three decades ago, 20 percent of the ice pack was more than four years old and just 35 percent of the pack was first-year ice, Richter-Menge said. “Given consistent projections of continued warming temperatures, we can expect to see continued widespread and sustained change throughout the Arctic environmental system,” she added.
Greenland is loosing ice mass quite rapidly for years, as this chart indicates:
Cumulative change in the total mass (in Gigatonnes, Gt) of the Greenland Ice Sheet between April 2002 and April 2015 |
The changing Arctic is impacting the rest of the planet as well, said Rick Spinrad, chief scientist with the National Oceanic and Atmospheric Administration (NOAA), which released the 2015 Arctic Report Card
“What happens in the Arctic doesn’t stay in the Arctic,” Spinrad said. “What happens matters to all of us from strategic, climate and national security perspectives.”