An Optimization/IT Theory Approach to the HOx Dilemma, Data, and Modeling
Abstract
Measurements of chemically active species in the mesosphere and upper stratosphere - O3, OH, HO2 - are poorly predicted by model calculations; the resulting HOx dilemma usually underpredicting O3 and HO2 but overpredicting OH. Some rate constant changes have been proposed for improvement. We have used results from the LLNL 2-D atmospheric model to perform a rigorous analysis of the coupling between representative MAHRSI, IR balloon, and microwave measurements and the sensitive rate parameters. By considering estimated observational and rate parameter error limits, our procedures compute which groups of observations are mutually inconsistent within the space of permissible kinetic variations. Possible kinetic revisions to optimize selected model predictions are also determined. This IT analysis procedure forms a basis to codify, sort, and analyze groups of representative data for atmospheric photochemical (or other kinetics) systems, and provides a means to reduce modeling error. The results require exclusion of 6 of the 39 target observations, particularly some low altitude (40 km) observations, and significant modifications to oxygen and ozone photolysis rates and the OH+O, OH+HO2, and O+HO2 rate constants. Research supported by the NASA ITM Program. Thanks to Dr. Peter Connell of LLNL for providing his model results.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2003
- Bibcode:
- 2003AGUFMSA51A0502S
- Keywords:
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- 0317 Chemical kinetic and photochemical properties;
- 0340 Middle atmosphere: composition and chemistry