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Photolysis of sulfuric acid vapor by visible light as a source of the polar stratospheric CN layer
- Source :
- Journal of Geophysical Research. 110
- Publication Year :
- 2005
- Publisher :
- American Geophysical Union (AGU), 2005.
-
Abstract
- [1] We present the first microphysical calculations confirming that photolysis of sulfuric acid vapor by visible light is responsible for the formation of the springtime “CN layer” observed in the polar stratosphere. Our calculations show that the recently proposed photolysis mechanism is also sufficient to explain observations of vertically increasing SO2 mixing ratios in the upper stratosphere. Such photolysis, however, does not sufficiently explain the limited observations above 40 km of vertically decreasing H2SO4 and SO3 vapor, suggesting an additional loss mechanism there. We rule out previous speculation regarding reaction of H2SO4 with O(1D) or OH as inconsistent with observations of SO2. Rather, the loss is consistent with a permanent sink for sulfur, such as H2SO4 neutralization by metals on meteoritic dust. In light of such removal, H2SO4 photolysis to SO2 gains added importance in preserving gaseous sulfur in the upper stratosphere. We also present new cross sections derived from ab initio calculations for H2SO4 absorption at visible and Lyman-α wavelengths and evaluate their atmospheric implications. Our atmospheric model reveals that photolysis of H2SO4 by Lyman-α radiation is responsible for up to one third of the SO2 in the mesosphere and 10% of the particles in the polar stratospheric CN layer.
- Subjects :
- Atmospheric Science
Materials science
Soil Science
chemistry.chemical_element
Aquatic Science
Oceanography
Photochemistry
Atmospheric sciences
Mesosphere
chemistry.chemical_compound
Geochemistry and Petrology
Earth and Planetary Sciences (miscellaneous)
Mixing ratio
Stratosphere
Earth-Surface Processes
Water Science and Technology
Ecology
Photodissociation
Paleontology
Forestry
Sulfuric acid
Sulfur
Geophysics
chemistry
Space and Planetary Science
Polar
Visible spectrum
Subjects
Details
- ISSN :
- 01480227
- Volume :
- 110
- Database :
- OpenAIRE
- Journal :
- Journal of Geophysical Research
- Accession number :
- edsair.doi...........bac10cf1b0ced60a1fed82ebbbe89679