UV Absorption Cross Sections of ClOOCl Are Consistent with Ozone Degradation Models
Hsueh-Ying Chen,1,*
Chien-Yu Lien,1,*
Wei-Yen Lin,1,2
Yuan T. Lee,1,2
Jim J. Lin1,3,
Recently, discrepancies in laboratory measurements of chlorine
peroxide (ClOOCl) absorption cross sections have cast doubt
on the validity of current photochemical models for stratospheric
ozone degradation. Whereas previous ClOOCl absorption measurements
all suffered from uncertainties due to absorption by impurities,
we demonstrate here a method that uses mass-selected detection
to circumvent such interference. The cross sections of ClOOCl
were determined at two critical wavelengths (351 and 308 nanometers).
Our results are sufficient to resolve the controversial issue
originating from the ClOOCl laboratory cross sections and suggest
that the highest laboratory estimates for atmospheric photolysis
rates of ClOOCl, which best explain the field measurements via
current chemical models, are reasonable.
2 Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan.
3 Department of Applied Chemistry, National Chiao Tung University, Hsinchu 30010, Taiwan.
* These authors contributed equally to this work.
To whom correspondence should be addressed. E-mail: jimlin{at}gate.sinica.edu.tw
