Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published June 1994 | Published
Journal Article Open

Aircraft-borne, laser-induced fluorescence instrument for the in situ detection of hydroxyl and hydroperoxyl radicals

Abstract

The odd-hydrogen radicals OH and HO2 are central to most of the gas-phase chemical transformations that occur in the atmosphere. Of particular interest is the role that these species play in controlling the concentration of stratospheric ozone. This paper describes an instrument that measures both of these species at volume mixing ratios below one part in 10^14 in the upper troposphere and lower stratosphere. The hydroxyl radical (OH) is measured by laser induced fluorescence at 309 nm. Tunable UV light is used to pump OH to the first electronic state (A-tilde 2Sigma+(v[script ']=1) <-- X-tilde 2Pi3/2 (v[script `]=0)) near 282 nm. The laser light is produced by a high-repetition rate pulsed dye-laser powered with all solid-state pump lasers. HO2 is measured as OH after gas-phase titration with nitric oxide. Measurements aboard a NASA ER-2 aircraft demonstrate the capability of this instrument to perform reliably with very high signal-to-noise ratios (>~30) achieved in short integration times (< 20 sec).

Additional Information

© 1994 American Institute of Physics. Received 17 January 1994; accepted 4 March 1994) We would like to thank the many individuals whose efforts led to the success of this experiment. At Harvard: E. Weinstock, A. Dessler, H. Michelsen, E. Thompson, T. Martin, E. Schomp, R. Mendelson, J, Canavan, D. Spillane, F. DeFreze, G. Graves, R. Heroux, K. Perkins, D. Chartrand, P. Guay, P. Rossi, J. Greer, and J. McDonough; At NASA Ames: S. Hipskind, E. Condon, and S. Wegener, J. Barrilleaux and the pilots of the ER-2. Cooperation with the Lockheed engineering staff, H. Kent, G. Prince, and R. York, is gratefully acknowledged. A special thanks to A. Schmeltekopf for his support before and help during the integration of the instrument onto the aircraft. This project would not have been possible without the pioneering work of R.M. Stimpfle. This work funded in part by the NASA HSRP Program with addition support from the NASA High Altitude Branch. P.O. Wennberg gratefully acknowledges personal support from NSF and Hughes Graduate Fellowships.

Attached Files

Published - WENrsi94.pdf

Files

WENrsi94.pdf
Files (2.7 MB)
Name Size Download all
md5:9b6d406b592db6b3f9b3f4f0b8f47531
2.7 MB Preview Download

Additional details

Created:
August 22, 2023
Modified:
October 16, 2023