A simple scheme for partitioning aircraft-easured ozone fluxes into surface-uptake and chemical transformation

• Published in: Atmospheric environment (1994) 1995-11, Vol.29 (21), p.3199-3207
• Main Authors: Guo, Y., Desjardins, R.L., Macpherson, J.I., Schuepp, P.H.
• Format: Article
• Language: English
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/1352-2310(95)00088-G

The interplay between surface uptake and atmospheric chemistry makes aircraft-measured ozone fluxes near the surface complex to interpret over such surfaces as recently, cultivated bare soil, newly cut hay, cities and near highways in the San Joaquin Valley of California (the California Ozone Deposition Experiment, 1991). In this study, a simple partitioning scheme is proposed, based on the estimation of the ozone surface;-uptake rate by a regressional fit of ozone flux vs latent heat flux and a vegetation index, over well-irrigated vegetative surfaces, by assuming that ozone flux residuals are due to atmospheric chemistry. The contributions to ozone fluxes by atmospheric chemistry over surfaces other than well-irrigated vegetative surfaces can then be estimated from the difference between the estimated ozone surface-uptake rate and the measured ozone flux. The estimates indicate that chemical contributions are more significant than surface-uptake and that the chemical contributions are dominated primarily by ozone destruction over recently cultivated bare soil, newly cut hay, city and near highway. The dominant sink for ozone destruction is analytically shown to be caused by NO concentrations in excess of the photostationary state, which are believed to be linked to the strong NO emissions from the surfaces.