The amount of summer sea ice in the Arctic fell this year to the second-lowest ever recorded by satellite.
NASA and the National Snow and Ice Data Center in Boulder, Colo. announced Thursday that the Arctic has reached its summer season low extent.
The 4.14 million square kilometers of ice measured on Sept. 10 is statistically tied with the minimum ice extent during the summer of 2007 for second place on the historic minimum list. This year’s minimum ice cover is more than two million square kilometers below the 1981-2010 mean.
Arctic Summer Minimum Sea Ice Extent Record, 2007-2016
|YEAR||EXTENT (millions of km2)||DATE MEASURED|
|1979-2000 mean||6.70||Sept. 13|
|1981-2010 mean||6.22||Sept. 15|
A statement released by NSIDC starkly described the conditions in the Arctic this summer:
“This year’s minimum extent is 750,000 square kilometers (290,000 square miles) above the record low set in 2012 and is well below the two standard deviation range for the 37-year satellite record.”
Cloudy skies and atmospheric pressure conditions slowed ice melt in June and July, which may have prevented this season from becoming the most ice-free summer ever observed from space.
“June and July are usually key months for melt because that’s when you have 24 hours a day of sunlight – and this year we lost melt momentum during those two months,” Walt Meier, a scientist at NASA’s Goddard Space Flight Center, said in a statement.
The pace of melting accelerated in August when two cyclones crossed the Arctic Ocean.
Meier explained that these may have especially impacted the speed with which ice in the Chukchi and Beaufort seas melted.
The three-and-one-half decade long satellite record shows a marked decline in the mean extent of Arctic sea ice during each month of the year.
In fact, a paper published on Sept. 15 in the journal Remote Sensing of Environment concluded that no record for maximum Arctic sea ice extent has been set since 1986, while during the 37 years of satellite monitoring there have been 75 new minimum ice extent records set.
“The record makes it clear that the ice is not rebounding to where it used to be, even in the midst of winter,” Claire Parkinson, the lead author of that study and a senior climate scientist at GSFC, said.
Arctic sea ice ordinarily reaches its maximum reach for the year in March, late in the winter. The sun is not visible in the region during the winter and does not contribute much to warming of land and sea surfaces during that season.
NSIDC’s statement cautioned that the estimate released Thursday could be revised if late-summer winds or other factors causing ice melt impact the sea ice cover during the remaining days of summer.
The monitoring record dates to 1978.
Earth’s poles are the two regions of the planet that are most sensitive to warming of the atmosphere. As sea ice melts, more solar energy is absorbed by the Arctic Ocean. The deep and dark waters absorb about 90 percent of the sun’s energy that reaches them.
By contrast, expansion of sea ice during the colder autumn and winter months causes about 80 percent of the solar energy that hits the frozen surface of the region’s marine environment to be reflected to space.
Humanity’s ongoing alteration of Earth’s atmosphere has now caused eleven straight months of record heat.
The National Oceanic & Atmospheric Administration announced April 19 that March continued the streak with an average worldwide temperature that was 2.2 degrees Fahrenheit above the twentieth century average for the month.
The month cemented the place of 2016’s first quarter as the warmest three-month period, relative to the norm, in recorded history.
“The departures are what we would consider astronomical,” NOAA climate scientist Jessica Blunden told the Associated Press. “It’s on land. It’s in the oceans. It’s in the upper atmosphere. It’s in the lower atmosphere. The Arctic had record low sea ice.”
“Everything everywhere is a record this month, except Antarctica,” Blunden continued in her AP interview. “It’s insane.”
March 2016 exceeded the previous record departure from the March mean for the period 1880-2016 by 0.54 degrees Fahrenheit.
The heat was particularly evident over land, where air temperatures last month were 4.19 degrees Fahrenheit above the twentieth century mean.
The agency also said that the average temperature above both land and sea surfaces across the globe during the first three months of this year was 2.07 degrees Fahrenheit higher than the twentieth century average. That is another record, exceeding the previous record set last year by 0.5 degrees Fahrenheit.
In the United States record heat was experienced in nearly every part of the country.
Deke Arndt, the leader of the climate monitoring branch at NOAA’s National Centers for Environmental Information, wrote in an April 12 blog post that every one of the nation’s climate divisions – sections distinguished by long-term climate patterns – was “warmer than normal” last month.
“The nationwide warmth was the result of unusual, and in some cases, record warmth, generally moving west to east across the CONUS,” Arndt wrote.
The acronym CONUS refers to the continental United States.
Up in the Arctic, the seasonal ice cover continued to shrink in March.
The average amount of territory in the Arctic that was covered by ice during the month was 7.02 percent below the 1981-2010 average and was the second-smallest ice cover during March since record-keeping began in 1979.
Arctic sea ice reached its maximum extent on March 24. Covering 14.52 million square kilometers (5.61 million square miles), it was the smallest maximum on record and was 1.12 million square kilometers (431,000 square miles) below average.
“I’ve never seen such a warm, crazy winter in the Arctic,” Dr. Mark Serreze, director of the National Snow and Ice Data Center in Boulder, Colo. and a professor of geography at the University of Colorado, said. “The heat was relentless.”
Serreze explained that, while the powerful El Nino that occurred this past winter may have helped drive down Arctic ice cover by causing circulation of warm air currents, the overall trend downward cannot be attributed to ENSO events.
“The system has always been variable,” he said. “It’s not like we’re going to set a new record each year. That’s not how the system works. If we recovered in the next year or two that would not be a surprise at all, but it would only be a temporary recovery.”
The average air temperature in the Arctic between Dec. 1 – Feb. 28 was 4-11 degrees Fahrenheit above average for that time period, according to an NSIDC press release.
Earth’s north polar ice cap was smaller this past winter than at any time since measurements began to be obtained by satellite, breaking a record set only last year.
NASA and the National Snow and Ice Data Center announced March 28 that the maximum extent of ice during the season was reached on March 24 and that it covered 14.52 million square kilometers.
That beat last year’s mark of 14.54 million square kilometers and continued a stretch in which the 13 most ice-free winters in the Arctic have occurred in the past 13 years.
“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,” Walt Meier, a sea ice scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said. “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.”
During the most recent winter season the Arctic experienced record high temperatures in December, January, and February. Air temperatures were as much as 10 degrees Fahrenheit higher than average at the edge of the ice pack, Meier said.
Warm air from the south was brought by winds to the Arctic, which also would have contributed to a lessened sea ice cover.
Less winter sea ice causes the air temperature over the Arctic ocean to increase because the unfrozen ocean waters are warmer than the overlaying air mass. As the ocean water evaporates, more water vapor accumulates in the atmosphere and that, in turn, causes clouds to form. Increased cloudiness causes an increase in surface warmth.
Satellite measurements of Arctic winter ice extent began in 1979.
Since that time the Arctic has lost nearly 1,606 square kilometers of winter sea ice. That is an area twice the size of Texas.
January continued a streak of hotter-than-average months, according to the National Oceanic & Atmospheric Administration, going into the record books as the hottest January since climate records have been kept and continuing a recent streak of consecutive warmest monthly temperature benchmarks.
According to the National Centers of Environmental Information, a bureau of NOAA, the worldwide average atmosphere and ocean surface temperature was 1.04 degrees Celsius above the 2oth century average. That is the second-highest deviation from the global norm ever recorded in 137 years of record-keeping, trailing only December 2015.
NASA’s Goddard Institute for Space Studies released data last week indicating that January represented the greatest departure from the global average atmosphere and ocean surface temperature, with the worldwide measurement reaching 1.13 degrees above the global average of the last century.
The record-breaking warmth was especially pronounced in the Arctic, where temperatures above 75 degrees north latitude were 7 degrees Celsius above average and temperatures. That would explain the report released last week by the National Snow & Ice Data Center, which indicated that January’s Arctic ice pack is lower than it has been in any January in recorded history. The NSIDC data shows that January’s Arctic ice pack was more than a million square kilometers less than the 1981-2010 average.
The NOAA report indicated that Sub-Saharan Africa, most of South America, the Middle East, and southwestern Asia also experienced significant warmth last month. Some areas experienced anomalous rainfall, particularly the United Kingdom, Ireland, some parts of western Europe, New Zealand, parts of Brazil and southern South America, and parts of China. Others were abnormally dry. Those areas included parts of Mexico and northern South America, some areas in Australia, portions of Asia, and a small part of northwestern Africa.
January was also the ninth consecutive month in which the record for highest average monthly air and sea surface temperature has been broken, according to NOAA.
1976 was the last year in which Earth experienced a January that was colder than average.