Index Geophysics

A photochemical model and sensitivity study of the triple-oxygen isotopic (Δ17O) composition of NOy, HOx, and H2O2 in a polluted boundary layer

We present a photochemical model developed for the <i>explicit</i> calculation of triple oxygen isotopic compositions (&Delta;¹⁷O) of major atmospheric species. While we focus on the &Delta;¹⁷O of HNO₃ and aerosol nitrate (NO^&minus;₃) and its precursors such as NO, NO₂ and N₂O₅, the general implementation given here also provides &Delta;¹⁷O predictions for other important atmospheric compounds such as OH, H₂O₂, and HO₂. Through the use of a simple aerosol surface area model, we calculate the &Delta;¹⁷O composition of aerosol nitrate produced as a function of aerosol size and aerosol surface type. We explore the sensitivity of the &Delta;¹⁷O of atmospheric species through a series of sensitivity studies and show that the &Delta;¹⁷O of atmospheric compounds is affected to various degrees by environmental factors such as temperature, relative humidity, ozone concentration, NO_x flux, and total ozone column density. In addition, we find that &Delta;¹⁷O of these species is sensitive to photochemical conditions such as cloud albedo, latitude, and time of year. We compare the &Delta;¹⁷O calculation outputs to previous methods and find significant differences in the &Delta;¹⁷O of NO₂. We describe the origins of these and suggest studies that may help to resolve these differences.

Dominguez, G.

Wilkins, G.

Thiemens, M. H.

2018-08-10

Text

application/pdf

10.5194/acpd-9-13355-2009

https://acp.copernicus.org/preprints/acp-2009-317/

eISSN: 1680-7324

eng