It might be time to retire the groundhog and begin monitoring Arctic sea ice for a greater prediction of late-winter climate.
On March 15, the Arctic sea ice reached its most extent ― probably the most ice the frigid North would see this yr, in keeping with the Nationwide Snow & Ice Knowledge Middle (NSIDC) in Boulder, Colo. Adjustments in Arctic ice, and its complete extent, could also be affecting climate additional south, scientists suppose.
The ice lined 5.84 million sq. miles (15.13 million sq. kilometers), the sixth-lowest space on document since 1979. Many of the ice was younger, first-year ice, freshly frozen. The Arctic additionally has multiyear ice, frozen year-round, which is stiffer and thicker, and comprises a lot much less brine than first-year ice does. Nonetheless, its slice of the entire ice pie has been shrinking in recent times.
In the course of the 2012 to 2013 winter season, the ocean ice grew a document four.53 million sq. miles (11.72 million sq. km). This large development was primarily as a consequence of final yr’s lacking ice: A record-low ice minimum in September 2012 meant extra ocean was uncovered, leaving a higher space uncovered to refreeze this winter, the NSIDC stated in an announcement.
The large swings between summer time and winter ice point out a shift towards a extra pronounced seasonal cycle within the Arctic, in keeping with the NSIDC.
The shift is altering the ratio of skinny, first-year ice to thick, multiyear ice, which is extra immune to summer time melting and winter storms. First-year ice more and more dominates the Arctic ice pack, the NSIDC stated.
This yr, the comparatively fragile first-year ice was buffeted by a robust Arctic storm in February, extensively fracturing the ice. Cracking from storms occurs yearly. This yr, nonetheless, the rifts prolonged from Canada to Alaska ― though they shortly refroze.
Much less Arctic ice additionally means extra of the ocean and environment can heat from the solar. Scientists suppose this warming shifts the jet stream, steering chilly storm programs additional south. March introduced freezing temperatures and powerful winter storms to the USA, Europe and Russia.
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