Quantitative detection of iodine in the stratosphere.

Autor: Koenig TK; Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309.; Cooperative Institute for Research in Environmental Sciences, Boulder, CO 80309., Baidar S; Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309.; Cooperative Institute for Research in Environmental Sciences, Boulder, CO 80309., Campuzano-Jost P; Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309.; Cooperative Institute for Research in Environmental Sciences, Boulder, CO 80309., Cuevas CA; Department of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Rocasolano, Spanish National Research Council, 28006 Madrid, Spain., Dix B; Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309., Fernandez RP; Department of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Rocasolano, Spanish National Research Council, 28006 Madrid, Spain.; Institute for Interdisciplinary Science (ICB), School of Natural Sciences (FCEN), National University of Cuyo (UNCUYO) and National Research Council (CONICET), Mendoza 5501, Argentina., Guo H; Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309.; Cooperative Institute for Research in Environmental Sciences, Boulder, CO 80309., Hall SR; Atmospheric Chemistry Observations and Modeling Laboratory, National Center for Atmospheric Research, Boulder, CO 80301., Kinnison D; Atmospheric Chemistry Observations and Modeling Laboratory, National Center for Atmospheric Research, Boulder, CO 80301., Nault BA; Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309.; Cooperative Institute for Research in Environmental Sciences, Boulder, CO 80309., Ullmann K; Atmospheric Chemistry Observations and Modeling Laboratory, National Center for Atmospheric Research, Boulder, CO 80301., Jimenez JL; Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309.; Cooperative Institute for Research in Environmental Sciences, Boulder, CO 80309., Saiz-Lopez A; Department of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Rocasolano, Spanish National Research Council, 28006 Madrid, Spain., Volkamer R; Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309; rainer.volkamer@colorado.edu.; Cooperative Institute for Research in Environmental Sciences, Boulder, CO 80309.
Jazyk: angličtina
Zdroj: Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2020 Jan 28; Vol. 117 (4), pp. 1860-1866. Date of Electronic Publication: 2020 Jan 13.
DOI: 10.1073/pnas.1916828117
Abstrakt: Oceanic emissions of iodine destroy ozone, modify oxidative capacity, and can form new particles in the troposphere. However, the impact of iodine in the stratosphere is highly uncertain due to the lack of previous quantitative measurements. Here, we report quantitative measurements of iodine monoxide radicals and particulate iodine (I y,part ) from aircraft in the stratosphere. These measurements support that 0.77 ± 0.10 parts per trillion by volume (pptv) total inorganic iodine (I y ) is injected to the stratosphere. These high I y amounts are indicative of active iodine recycling on ice in the upper troposphere (UT), support the upper end of recent I y estimates (0 to 0.8 pptv) by the World Meteorological Organization, and are incompatible with zero stratospheric iodine injection. Gas-phase iodine (I y,gas ) in the UT (0.67 ± 0.09 pptv) converts to I y,part sharply near the tropopause. In the stratosphere, IO radicals remain detectable (0.06 ± 0.03 pptv), indicating persistent I y,part recycling back to I y,gas as a result of active multiphase chemistry. At the observed levels, iodine is responsible for 32% of the halogen-induced ozone loss (bromine 40%, chlorine 28%), due primarily to previously unconsidered heterogeneous chemistry. Anthropogenic (pollution) ozone has increased iodine emissions since preindustrial times (ca. factor of 3 since 1950) and could be partly responsible for the continued decrease of ozone in the lower stratosphere. Increasing iodine emissions have implications for ozone radiative forcing and possibly new particle formation near the tropopause.
Competing Interests: The authors declare no competing interest.
Databáze: MEDLINE
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