Monoterpene hydrocarbons in the nighttime troposphere
Monoterpene hydrocarbons were measured during the night at a rural site in the Rocky Mountains. The compounds positively identified and quantified were ..cap alpha..-pinene, camphene, ..beta..-pinene, ..delta../sup 3/-carene, and d-limonene. The average sum of the mixing ratios of the five compounds measured during the nighttime between July and Oct., 1982, was 0.63 ppb (volume), which was about twice the corresponding daytime average sum. No significant difference was observed between day and night in the relative concentrations of the individual monoterpenes. Increased atmospheric stability, with attendant reduced mixing and dilution during the night, was found to contribute to the large nighttime vs. daytime monoterpene mixing ratios. Nighttime atmospheric stability was also responsible for the observation of ozone diminution and a corresponding inverse relationship between monoterpene and ozone mixing ratios. The results indicate that, at this site, transport rather than chemistry determines the concentrations of the monoterpenes. The ultimate fate of the monoterpenes is chemical reaction with O/sub 3/, OH, or NO/sub 3/. Because of the differences in rate constants of reactions between the various monoterpenes and the above species, chemical reaction should cause systematic changes in relative concentrations of monoterpenes, which are characteristic of the reactant species involved.
- Research Organization:
- National Oceanic and Atmospheric Administration/Environmental Research Labs., Boulder, CO
- OSTI ID:
- 5611560
- Journal Information:
- Environ. Sci. Technol.; (United States), Vol. 19:4
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
TERPENES
ATMOSPHERIC CHEMISTRY
CAMPHENE
CHEMICAL REACTIONS
CORRELATIONS
DAILY VARIATIONS
EARTH ATMOSPHERE
ECOLOGICAL CONCENTRATION
ENVIRONMENTAL TRANSPORT
MIXING
NATURAL OCCURRENCE
OZONE
ROCKY MOUNTAINS
RURAL AREAS
TROPOSPHERE
ALKENES
CHEMISTRY
CYCLOALKENES
HYDROCARBONS
MASS TRANSFER
MOUNTAINS
ORGANIC COMPOUNDS
VARIATIONS
500200* - Environment
Atmospheric- Chemicals Monitoring & Transport- (-1989)