PT  - JOURNAL ARTICLE
AU  - Vaida, V.
AU  - Kjaergaard, H. G.
AU  - Hintze, P. E.
AU  - Donaldson, D. J.
TI  - Photolysis of Sulfuric Acid Vapor by Visible Solar Radiation
AID  - 10.1126/science.1079297
DP  - 2003 Mar 07
TA  - Science
PG  - 1566--1568
VI  - 299
IP  - 5612
4099  - http://science.sciencemag.org/content/299/5612/1566.short
4100  - http://science.sciencemag.org/content/299/5612/1566.full
SO  - Science2003 Mar 07; 299
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.