An unusually strong storm formed off the coast of Alaska on August 5, 2012, and tracked into the center of the Arctic Ocean, where it lingered for several days. The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Aqua satellite captured this natural-color image on August 7, 2012. The center of the storm was located in the middle of the Arctic Ocean at the time.
The storm had an unusually low central pressure area. “It’s an uncommon event, especially because it’s occurring in the summer,” said Paul Newman, chief scientist for atmospheric sciences at NASA’s Goddard Space Flight Center. “Polar lows are more usual in the winter.” Newman estimated that there have only been about eight storms of similar strength during the month of August over the past 34 years of satellite records.
“It seems that this storm has detached a large chunk of ice from the main sea ice pack,” said Claire Parkinson, a climate scientist at NASA Goddard who studies ice. “This could lead to a more serious decay of the summertime ice cover than would have been the case otherwise, even perhaps leading to a new Arctic sea ice minimum.”
Arctic storms can have a large impact on sea ice, causing it to melt rapidly. Storms can tear off large swaths of ice and push them to warmer sites; they can churn the ice and make it slushier; or they can pull warmer waters up from the depths of the Arctic Ocean. “Decades ago, a storm of the same magnitude would have been less likely to have as large an impact on the sea ice because the ice cover was thicker and more expansive,” Parkinson added.
In the Arctic, sea ice extent fluctuates with the seasons. It reaches its peak extent in March, near the end of Northern Hemisphere winter, and its minimum extent in September, at the end of the summer thaw. In September 2007, Arctic sea ice extent was the smallest area on record since satellites began collecting measurements about 30 years ago.