Unprecedented Arctic ozone hole in 2011; a Florida tropical storm next week?: An unprecedented ozone hole opened in the Arctic during 2011, researchers reported this week in the journal Nature. Holes in the Antarctic ozone layer have opened up each spring since the early 1980s, but the Arctic had only shown modest springtime ozone losses in the 5% – 30% range over the past twenty years. But this year, massive ozone destruction of 80% occurred at altitudes of 18 – 20 kilometers in the Arctic during spring, resulting in Earth’s first known case of twin ozone holes, one over each pole. During late March and portions of April, the Arctic ozone hole was positioned over heavily populated areas of Western Europe, allowing large levels of damaging ultraviolet rays to reach the surface. UV-B radiation causes skin damage that can lead to cancer, and has been observed to reduce crop yields in two-thirds of 300 important plant varieties studied (WMO, 2002.) The total loss of ozone in a column from the surface to the top of the atmosphere reached 40% during the peak of this year’s Arctic ozone hole. Since each 1% drop in ozone levels results in about 1% more UV-B reaching Earth’s surface (WMO, 2002), UV-B levels reaching the surface likely increased by 40% at the height of this year’s hole. We know that an 11% increase in UV-B light can cause a 24% decrease in winter wheat yield (Zheng et al., 2003), so this year’s Arctic ozone hole may have caused noticeable reductions in Europe’s winter wheat crop.
[What a mess…]
Source: Dr. Jeff Masters’ WunderBlog