In the Southern Hemisphere, the ice cover around Antarctica gradually expands from March to October each year.
In the Southern Hemisphere, the ice cover around Antarctica gradually expands from March to October each year. During this time the total ice area increases by 6 times to become larger than Russia. The sea ice then retreats at a faster pace, most dramatically around December, when Antarctica experiences constant daylight.
New research led by the University of Washington explains why the ice retreats so quickly: Unlike other aspects of its behavior, Antarctic sea ice is just following simple rules of physics.
The study was published March 28 in Nature Geoscience.
“In spite of the puzzling longer-term trends and the large year-to-year variations in Antarctic sea ice, the seasonal cycle is really consistent, always showing this fast retreat relative to slow growth,” said lead author Lettie Roach, who conducted the study as a postdoctoral researcher at the UW and is now a research scientist at NASA and Columbia University. “Given how complex our climate system is, I was surprised that the rapid seasonal retreat of Antarctic sea ice could be explained with such a simple mechanism.”
Previous studies explored whether wind patterns or warm ocean waters might be responsible for the asymmetry in Antarctica’s seasonal sea ice cycle. But the new study shows that, just like a hot summer day reaches its maximum sizzling conditions in late afternoon, an Antarctic summer hits peak melting power in midsummer, accelerating warming and sea ice loss, with slower changes in temperature and sea ice when solar input is low during the rest of the year.
Read more at: University of Washington
A research vessel in Antarctica on June 3, 2017, the first day researchers saw the sun rise above the horizon after weeks of polar darkness. New research shows that solar radiation drives the relatively fast annual retreat of sea ice around Antarctica at the end of each calendar year. (Photo Credit: Ben Adkison)
