Scientists from the USA, Spain and Argentina for the first time, quantitatively determine the content of iodine in the lower stratosphere and evaluated its effect on the destruction of ozone in it. According to estimates of authors of about 0.8 trillion shares by volume of inorganic iodine enters the stratosphere, contributing seven per cent of the contribution to loss of ozone in this layer. The results of the study, which will help to develop more accurate climate models, published in the journal Proceedings of the National Academy of Sciences.
Iodine is involved in catalytic reactions that destroy ozone and can lead to the formation of new particles which change the composition of clouds and their reflectivity. It is already known that in the upper troposphere due to anthropogenic emissions of bromine and iodine has been exceeded, but the role of iodine in ozone depletion in the stratosphere is much less studied due to lack of data on the content of this item.
Previously, scientists on measurements from the Ground or balloons was only able to determine the upper limit of the content of radicals of iodine monoxide (tenth trillion by volume) in the stratosphere. In the gas phase, iodine can exist in the form of compounds with oxygen, hydrogen, oxides of nitrogen, chlorine and bromine, which may be the cause of 30 percent ozone depletion in the lower stratosphere in the tropics. Great concentration is part of the radical monoxide iodine, which, according to assumptions in excess of the upper threshold (from 0.15 to 0.45 trilioni share volume) must be in the daytime in the stratosphere. The presence of iodine in the stratosphere could be as completely insignificant, and one of the main causes of ozone layer depletion.
Theodore Koenig (Koenig Theodore) with colleagues from the University of Colorado in boulder have done a series of research flights and quantitatively determined the content of radicals of iodine monoxide, and particulate iodine in the stratosphere. The content of radicals of iodine monoxide was determined using installed in the plane of the optical spectrometer, developed by scientists at the University of Colorado CU AMAX-DOAS. The particle concentration of iodine was determined using mass-spectrometer high-resolution CU HR-AMS.