Reducing the thickness of the ozone layer over the Arctic Scientists prove
An unusually long period of low temperatures this winter and spring has caused an unprecedented reduction in the thickness of the ozone layer over the Arctic. Studies show that the destruction of the ozone layer over the Arctic in 2011, comparable only with the appearance of the ozone hole over Antarctica in the mid-80s.
To study the loss in the ozone layer over the Arctic, scientists nine countries analyzed extensive data on daily observations of trace gases, clouds and ozone, meteorological data and atmospheric models. Scientists have noticed that at certain heights above the ground the cold period in the Arctic lasted more than 30 days than in any previous winters. This led to an extraordinary loss of ozone.
"Daily temperature in winter 2010/2011 has not been lower than in the previous winter. However, the difference is that the temperature was low enough for a longer period, to form chlorine forms that destroy ozone. This means that if the winter temperatures in the Arctic will fall even slightly, the thickness of the ozone layer will decrease, "- said Glorin Manny from NASA Jet Propulsion Laboratory and the Institute of Mining and Technology, New Mexico in Socorro.
It is known that at the time of the polar vortex is a destruction of the ozone layer. Area reduction of ozone over the Arctic is much less ozone hole over Antarctica. The reason is that the Arctic polar vortex was 40% less than a typical Antarctic vortex. Despite the fact that the Arctic vortex is smaller, it is more mobile and often goes over densely populated areas. Although the destruction of the ozone layer over the Arctic is almost 2 times less than the Antarctic destruction observed in the spring, they are comparable to the destruction only in some places, the ozone hole over Antarctica.
Gloria tells Manny that the atmospheric lifetime of chemicals that deplete the ozone layer, is large enough. This means that ozone depletion over the Arctic will continue for many years.
In the near future, however, the ability of scientists to quantify ozone loss in the polar regions may be reduced when running scientific satellites NASA CALIPSO and Aura will complete their work.
Photo: NASA / JPL-Caltech