Measuring OH and HO{sub 2} in the troposphere by laser-induced fluorescence at low pressure
- Pennsylvania State Univ., University Park, PA (United States)
The hydroxyl radical OH oxidizes many trace gases in the atmosphere. It initiates and then participates in chemical reactions that lead to such phenomena as photochemical smog, acid rain, and stratospheric ozone depletion. Because OH is so reactive, its volume mixing ratio is less than 1 part per trillion volume (pptv) throughout the troposphere. Its close chemical cousin, the hydroperoxyl radical HO{sub 2}, participates in many reactions as well. The authors have developed an instrument capable of measuring OH and HO{sub 2} by laser-induced fluorescence in a detection chamber at low pressure. This prototype instrument is able to detect about 1.4 X 10{sup 5} molecules cm{sup {minus}3} (0.005 pptv) of OH at the ground in a signal integration time of 30 s with negligible interferences. The absolute uncertainty is a factor of 1.5. This instrument is now being adapted to aircraft use for measurements throughout the troposphere. 25 refs., 7 figs.
- OSTI ID:
- 220220
- Journal Information:
- Journal of the Atmospheric Sciences, Vol. 52, Issue 19; Other Information: PBD: 1 Oct 1995
- Country of Publication:
- United States
- Language:
- English
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