Photochemistry of Arctic Ozone


 

Theory Investigation:Photochemistry of Arctic Ozone 
Principal Investigator:Ross J. Salawitch 
Co-Investigators:Gregory B. OstermanMarkus Rex
Organization:California Institute of Technology
Jet Propulsion Laboratory
Mail Stop 183-601
4800 Oak Grove Drive
Pasadena, CA 91109
 Alfred Wegener Institute for Polar and Marine Research
Bremerhaven, Germany

Investigation Description: Our investigation focuses on understanding:

  1. the factors that regulate the chemical loss rate of ozone when the concentration of ClO is highly perturbed;
  2. the mechanisms responsible for elevated levels of ClO;
  3. the phase and composition of polar c clouds.
We will use existing photochemical and thermodynamic models as well as established methods for gaining quantitative information from correlations of the mixing ratios of long long-lived tracers to study these problems [e.g., Osterman et al., 1997, 1999; Rex et al., 1999; Salawitch et al., 1988, 1989, 1993; Wofsy et al., 1990a, b]. Some of the outstanding research questions we plan to address include:

The answers to these questions will allow significant reduction in our uncertainty of model assessments of the future change in Arctic ozone due to human activities such as the build-up of greenhouse gases, exhaust from subsonic and supersonic aircraft, and the expected decline in chlorine loading due to the ban on the use of CFCs.

We will submit to the data archive files containing calculated photolysis rates and concentrations of reactive gases along the observation track of each balloon, DC-8, and ER-2 flight. We intend to work closely with the experimental investigators and other theory investigators in a close collaborative manner on interpretation of the SOLVE measurements. Each of the major areas of focus described above will benefit from combined use of the data from the different platforms.

 

References:

Osterman, G. B., R. J. Salawitch, B. Sen, G. C. Toon, R. A. Stachnik. H. M. Pickett, J. J. Margitan, J.-F. Blavier, and D. B. Peterson, Balloon-borne measurements of stratospheric radicals and their precursors: implications for the production and loss of ozone, Geophys. Res. Lett., 24, 1107-1110, 1997.
Osterman, G. B., B. Sen, G. C. Toon, R. J. Salawitch, J. J. Margitan, J.-F. Blavier, D. W. Fahey, and R. S. Gao, Partitioning of NOy species in the summer Arctic stratosphere, Geophys. Res. Lett., 26, 1157-1160, 1999.
Rex, M., R. J. Salawitch, G. C. Toon, B. Sen, J. J. Margitan, G. B. Osterman, J.-F. Blavier, R. S. Gao, S. Donnelly, E. Keim, J. Neumann, D. W. Fahey, C. R. Webster, D. C. Scott, R. L. Herman, R. P. May, E. J. Moyer, M. R. Gunson, F. W. Irion, A. Y. Chang, C. P. Rinsland, and T. P. Bui, Subsidence, mixing, and denitrification of Arctic polar vortex air measured during POLARIS, J. Geophys. Res., accepted, 1999.
Salawitch, R. J., S. C. Wofsy, and M. B. McElroy, Influence of polar stratospheric clouds on the depletion of Antarctic ozone, Geophys. Res. Lett., 15, 871-874, 1988.
Salawitch, R. J., G. P. Gobbi, S. C. Wofsy, and M. B. McElroy, Denitrification of the Antarctic stratosphere, Nature, 339, 525-527, 1989.
Salawitch, R. J., S. C. Wofsy, E. W. Gottlieb, D. W. Toohey, L. M. Avallone, L. R. Lait, P. A. Newman, M. R. Schoeberl, M. Loewenstein, J. R. Podolske, S. E. Strahan, A. Weaver, J. H. Proffitt, C. R. Webster, R. D. May, D. W. Fahey, D. Baumgardner, J. E. Dye, J. C. Wilson, K. K. Kelly, J. W. Elkins, K. R. Chan, and J. G. Anderson, Chemical loss of ozone in the Arctic polar vortex in the winter of 1991-92, Science, 261, 1146-1149, 1993.
Wofsy, S. C., G. P. Gobbi, R. J. Salawitch, and M. B. McElroy, Nucleation and growth of HNO3×3H2O particles in the polar stratosphere, J. Atmos. Sci., 47, 2004-2012, 1990a.
Wofsy, S. C., R. J. Salawitch, J. H. Yatteau, M. B. McElroy, B. W. Gandrud, J. E. Dye, and D. Baumgardner, Condensation of HNO3 on falling ice particles: Mechanism for denitrification of the polar stratosphere, Geophys. Res. Lett., 17, 449-452, 1990b.