Melting of the ice increased allocation of bromine on the ozone layer

© NASA. JPL-Caltech/University of Bremen

March 2. The scientists found that the melting of the "young" sea ice, replacing perennial ice fields in the process of climate change, the atmosphere receives more bromine, which is destructive effects on the ozone layer, the site of NASA.

A study conducted by a group of scientists from the U.S., Canada, Germany and the UK as part of NASA BROMEX (Bromine, Ozone, and Mercury Experiment) showed that the melting of the ice due to warming in the Arctic, can cause progressive contamination of the region bromine compounds.

"The reduction in sea ice in summer has attracted much attention to the possible use of the transport and resource potential of the Arctic, but the change in the chemical composition of sea ice due to climate change impact on the environment … In the future, it may cause increased pollution bromine region", — said the head Research, Laboratory of NASA's Jet Propulsion in Pasadena (California, USA) Dream Ngim (Son Nghiem), whose words are reported.

The natural abundance of bromine, chlorine and other halogens in the atmosphere is maintained by a number of sources: the generation of these gases in the troposphere, the allocation to the marsh surface, when burning oil wells and volcanic eruptions. However, the most important source of halogens in the atmosphere — sea salt, from which they are released, in particular, during the melting of sea ice.

Young ice "salty" long-term, because they have not time to go through the process of natural desalination. As a result of the melting of ice in the atmosphere of the young stand many times higher doses of halogens. Most environmentally "problem" of them is bromine, reacts with ozone to form gipobromidov — a powerful, completely disinfecting substances, analogues of which are used by humans for disinfection and etching. Thus, elevated levels of free bromine in the atmosphere, "corroding" the ozone layer and are deposited in the form of caustic, toxic compounds.

First of bromide contamination in the polar regions are talking about two decades ago. In the atmosphere over the Arctic and Antarctic combination of low temperatures and high radiation activity of the sun is such that the mercury is usually quite inert element is oxidized. As a result of the so-called "bromine explosion" — the growth of free bromine in the atmosphere — is a reaction of bromine with mercury vapor, toxic products which are deposited on the water, ice and air transfer from the region.

On the example of the Canadian Arctic researchers were able to show that bromine compounds are transported only in the lower troposphere, up to two thousand feet. Similar findings were made when the scientists examined the mountain ranges of Alaska and Canada, which served as a kind of "vertical scale" deposition of bromine. Thus, the high mountain ranges of 2.5-3 thousand meters can serve as barriers to prevent bromine beyond the Arctic, inhabited parts of the continent.

To model the future picture bromine Arctic pollution researchers analyzed data from six satellites of NASA, ESA and the Canadian Space Agency, conducted a series of field observations and combining these data with models of air flow over the polar region. The study appears in the journal Journal of Geophysical Research — Atmospheres.

Source: RIA Novosti

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