Photochemistry of formaldehyde during the 1993 Tropospheric OH Photochemistry Experiment
- 20 March 1997
- journal article
- Published by American Geophysical Union (AGU) in Journal of Geophysical Research: Atmospheres
- Vol. 102 (D5), 6283-6296
- https://doi.org/10.1029/96jd03249
Abstract
The present study examines in detail the photochemistry of the important hydrocarbon intermediate HCHO during the 1993 Fritz Peak/Idaho Hill OH Photochemistry Experiment. Measurement‐model relationships for HCHO were studied employing a box model with input measurements of hydrocarbons, photolysis frequencies, NOx, and HOx measured at the Idaho Hill sampling site during clean westerly flow. Tunable diode laser absorption and long‐path UV‐visible absorption spectroscopic techniques provided the high‐quality time‐resolved ambient HCHO database necessary for this study. For clear sky conditions during clean westerly flow, midday HCHO measurements and model calculations were in agreement to within 12% under various realistic model scenarios. This is significant since it places constraints on the OH concentrations as well as the characteristics of potential missing hydrocarbons necessary to balance measured and modeled OH. Measurement relationships between HCHO and CH3CHO were also investigated; polluted air from the Denver‐Boulder front range resulted in the following linear regression: [HCHO] = (0.62±0.20) ppbv + (1.83±0.15) CH3CHO. The slope reflects the large if not dominant influence of primary and biogenic emissions, and the intercept reflects the existence of HCHO sources which are not sources of CH3CHO. Clean westerly flow produced a significantly different relationship with no obvious correlation, and this is consistent with smaller biogenic sources of CH3CHO compared with the much larger known biogenic sources of HCHO.Keywords
This publication has 47 references indexed in Scilit:
- Meteorological characteristics and spatial extent of upslope events during the 1993 Tropospheric OH Photochemistry ExperimentJournal of Geophysical Research: Atmospheres, 1997
- Tunable diode laser absorption spectrometer for ground‐based measurements of formaldehydeJournal of Geophysical Research: Atmospheres, 1997
- Nonmethane hydrocarbon measurements during the Tropospheric OH Photochemistry ExperimentJournal of Geophysical Research: Atmospheres, 1997
- Sources and sinks of formaldehyde and acetaldehyde: An analysis of Denver's ambient concentration dataAtmospheric Environment, 1996
- Gas phase formaldehyde and peroxide measurements in the Arctic atmosphereJournal of Geophysical Research: Atmospheres, 1994
- Production of aldehydes as primary emissions and from secondary atmospheric reactions of alkenes and alkanes during the night and early morning hoursAtmospheric Environment. Part A. General Topics, 1993
- Peroxy radicals in the ROSE experiment: Measurement and theoryJournal of Geophysical Research: Atmospheres, 1992
- Emissions of volatile organic compounds from vegetation and the implications for atmospheric chemistryGlobal Biogeochemical Cycles, 1992
- Acuchem: A computer program for modeling complex chemical reaction systemsInternational Journal of Chemical Kinetics, 1988
- Theoretical study of the initial products of the atmospheric oxidation of hydrocarbonsJournal of Geophysical Research: Atmospheres, 1987