The Arctic and the Antarctic have experienced record lows of sea ice extent so far in 2017, according to the US National Snow and Ice Data Center (NSIDC), and in the Arctic, specifically, the sea ice was both thinner and scantier than ever before as measured by satellites, showing around 8.0 percent less ice than normal, reports Carbon Brief.
This new information on sea ice extent comes on the heels of an announcement earlier this week by the World Meteorological Organisation that confirmed the year 2016 “made history,” with record high global temperatures and record low sea ice. The report by the WMO also reminded us that those extremes have continued into this year.
Basically, the Arctic reached a record low wintertime maximum extent in the Northern Hemisphere on March 3, 2017, and the Antarctic reached its lowest ever recorded sea ice extent at the end of summer in the Southern Hemisphere on March 3, 2017, explains Phys.org.
‘Exceptional year’ in the Antarctic
For those of you following the sea ice extent at the poles, the Antarctic had an early maximum extent in 2016, followed by an early loss of ice beginning in September. Since November 2016, the sea ice extent has continued to be at its lowest since satellite record-keeping began 38 years ago.
This year’s annual sea ice minimum of 815,000 square miles (2.11 million square kilometers) was 71,000 square miles (184,000 square kilometers) below the previous lowest minimum extent in the satellite record, which occurred in 1997. Actually, record sea ice losses were set every month since November.
Dr. Mark Brandon, a polar oceanographer at the Open University, tells Carbon Brief: “Just a few years ago the Antarctic sea ice extent was breaking records as being relatively high, but this year it has shown record-breaking lows for several months.” Brandon cites the powerful El Nino the globe experienced recently as perhaps leaving some lasting “hangover effects” in Antarctica.
“A pattern of air pressure that determines the wind circulation in the high southern latitudes called the Southern Annular Mode switched from positive to negative in late 2016 and this may be linked to the large El Nino of 2014-16.” This switch made it “more mobile and likely led to the relatively early Antarctic spring”, explains Brandon.
Since March 3, the Antarctic sea ice has started growing again, even though it is a little slow. But scientists are keeping an eye over the winter on how the buildup will fare over the Southern Hemisphere’s winter. Keep in mind there is about 400,000 square kilometers of sea ice less than the previous minimum.
In the Arctic, it’s a question of “How low will it go?”
In the Arctic, the ice floating on the Arctic Ocean shrinks in a seasonal cycle from mid-March until mid-September. Then, as Arctic temperatures drop during Autumn and Winter, the sea ice grows to its maximum, usually in March. However, seasons and cycles of sea ice growth and shrinkage are not exactly normal in the Arctic.
Several events can be blamed on the record low sea ice winter maximum this year. First, there was a series of storms in the Atlantic that brought warmer waters to the Arctic, particularly in the Barents Sea, north of Scandinavia, causing it to remain almost ice-free. Added to this were the warmer-than-normal temperatures and winds that proved unfavorable to the formation of ice.
This year’s maximum extent was reached on March 7, when 5.57 million square miles (14.42 million square kilometers) was recorded. This is 37,000 square miles (97,00 square kilometers) below the previous record low, which occurred in 2015, and 471,000 square miles (1.22 million square kilometers) smaller than the average maximum extent for 1981 through 2010.
Based on satellite data and other records, Arctic sea ice maximums have been dropping about 2.7 percent per decade since 1978, while the summer minimums have been five times larger, or 13.5 percent per decade. Added to this, the ice is a lot thinner, leaving it vulnerable to the action of waves and currents, winds and warmer temperatures.
Photo by Nathan Kurtz/NASA.
“It has been a remarkable winter for the Arctic — very warm throughout the Arctic through pretty much all of the winter,” NASA scientist Walt Meier told BuzzFeed News by email.
“This winter, while remarkable, is part of a long-term trend towards lower winter sea ice extents and warmer winter temperatures that is seen in our long-term records, going back to 1979,” Meier said
