Fast chemical sensor for eddy-correlation measurements of methane emissions from rice paddy fields

Peter Werle, Robert Kormann
2001 Applied Optics  
A high-frequency-modulation spectrometer with a lead-salt diode laser operating in the 4 band of CH 4 at 7.8 m was used as a fast chemical sensor to measure ambient methane concentrations of 2 ppmv ͑parts in 10 6 volume-mixing ratio͒ with a time resolution of 10 Hz for micrometeorological flux measurements. To assess the quality of the data on methane emissions from rice paddy fields, we compared eddy-correlation measurements with simultaneously recorded emission data from the state-of-the-art
more » ... losed-chamber technique and showed that the closed-chamber measurements were 60%-90% higher than were the eddy-correlation measurements during the campaign. This outcome demonstrates that diode-laser spectroscopy is a valuable tool for quality assurance.
doi:10.1364/ao.40.000846 pmid:18357065 fatcat:x6h2xtfoufa2bj5omvpzijeyqy