Compared to the large ozone hole that forms over Antarctica each year, Arctic ozone loss has generally been much more limited. But in 2011, Arctic ozone declined to surprisingly low levels. What did climate have to do with it?
The low ice extent recorded this September continued the downward trend seen over the last 30 years. Meanwhile, scientists are finding that the ice cover has grown thinner, making it more vulnerable to melting during the summer.
Following a brief interlude of “neutral” sea surface temperature conditions this summer, La Niña has returned to the tropical Pacific Ocean. The cool phase of the El Niño-Southern Oscillation climate pattern is expected to persist through winter.
In summer 2011, the South was in the grip of one of the worst droughts on record, and the fall drought outlook issued by NOAA’s Climate Prediction Center provided little hope of relief, especially for the Southwest and Texas.
Each summer, the seasonal unraveling of the Arctic's blanket of ice exposes large areas of the ocean to solar heating. The smaller the ice extent, the larger the potential warming influence. Arctic sea ice extent in July 2011 was the lowest for that month in the satellite record.