RT Journal Article
SR Electronic
T1 Photolysis of Sulfuric Acid Vapor by Visible Solar Radiation
JF Science
JO Science
FD American Association for the Advancement of Science
SP 1566
OP 1568
DO 10.1126/science.1079297
VO 299
IS 5612
A1 Vaida, V.
A1 Kjaergaard, H. G.
A1 Hintze, P. E.
A1 Donaldson, D. J.
YR 2003
UL http://science.sciencemag.org/content/299/5612/1566.abstract
AB Atmospheric field measurements and models of the stratospheric sulfate aerosol layer led to the suggestion that sulfuric acid (H2SO4) must photolyze at high altitudes. We propose that excitation of vibrational overtones of H2SO4 and its hydrate in the near-infrared and visible leads to photolysis, forming sulfur trioxide (SO3) and water. On the basis of absorption cross sections calculated with ab initio methods calibrated to experimental measurements, we estimatedJ values that are sufficient to explain stratospheric and mesospheric sulfur dioxide (SO2) concentrations and the observation of the sulfate layer.