Airborne vacuum ultraviolet resonance fluorescence instrument for in situ measurement of CO

Citation
N. Takegawa et al., Airborne vacuum ultraviolet resonance fluorescence instrument for in situ measurement of CO, J GEO RES-A, 106(D20), 2001, pp. 24237-24244
Citations number
17
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Earth Sciences
Volume
106
Issue
D20
Year of publication
2001
Pages
24237 - 24244
Database
ISI
SICI code
Abstract
An airborne instrument for fast-response, high-precision measurement of tro pospheric carbon monoxide (CO) was developed using a vacuum ultraviolet (VU V) resonance fluorescence technique. The excitation radiation is obtained b y a DC discharge CO resonance lamp combined with an optical filter for the CO fourth positive band emission around 150 run. The optical filter consist s of a VUV monochromator and a crystalline quartz window (< 147-nm cutoff). The crystalline quartz window ensures a sharp: discrimination against wave lengths below 135.7 nm that yield a positive interference from water vapor. Laboratory tests showed that the optical system achieved a precision of 1. 1 parts per billion by volume (ppbv) at a CO concentration of 100 ppbv for a 1-s integration period, and the flow system provided a response time (Ile time constant) of similar to2 s. The aircraft measurement campaign Biomass Burning and Lightning Experiment-phase B (BIBLE-B) was conducted between A ugust and September 1999 over the western Pacific and Australia. The flight data obtained during this campaign were used to demonstrate the high preci sion and fast response of the instrument. An intercomparison of the VUV CO measurement and a gas chromatographic CO measurement was conducted during B IBLE-B. Overall, these two independent measurements showed good agreement, within the experimental uncertainties.