Coupling of ClOOCl and ClO in the Arctic polar vortex and evaluation of the polar inorganic chlorine budget
Abstract
The first measurements of ClOOCl in the stratosphere were acquired onboard the NASA ER-2 aircraft in the Arctic vortex during the winter of 1999--2000, thereby verifying the existence of ClOOCl and quantifying its potential role in polar ozone loss. An instantaneous photochemical steady-state approximation using measurements of the ratio of [ClOOCl] / [ClO]^2 constrains possible values of kprod / J and kprod / kloss(=Keq) for day and nighttime observations, respectively, where kprod is the dimer production rate constant, kloss is the thermal dissociation rate constant, Keq is the dimer thermal equilibrium constant, and J is the dimer photolysis rate calculated with a radiative model. Measurements of ClONO_2, HCl, and Cl_y, in addition to ClO and ClOOCl, permit analysis of chlorine activation and recovery throughout the polar winter and enable the first analysis of the inorganic chlorine budget in the Arctic vortex. Results reflect recently resubmitted ClO data, which incorporate a new understanding of the effect of the ClOO+NO reaction at low temperatures on the Harvard Halogen instrument performance.
- Publication:
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EGS - AGU - EUG Joint Assembly
- Pub Date:
- April 2003
- Bibcode:
- 2003EAEJA....12594W