REAL TIME CONTINUOUS MEASUREMENTS OF [CO2] AND δ13C AT MULTIPLE LOCATIONS USING CAVITY ENHANCED LASER ABSORPTION
Abstract
A commercial instrument (Los Gatos Research, model 908-0003) utilizing Cavity Enhanced Laser Absorption Spectroscopy was deployed in 2009 at the ZERT carbon release site (Bozeman, MT) for real time measurement of above-ground CO2 concentration and isotope ratio (δ13C). An automated switching system sampled 13 different locations in the field, as well as two known references, over an 8 day period. Real-time Keeling plots were constructed showing distinct signatures of soil (-27.0 ‰) and fossil (-56.0 ‰) sources compared to background air (-8.2 ‰). Instrument performance gave 0.2 ‰ precision with only 100 seconds of averaging per inlet. Sequential sampling of the various inlets gave a temporal and physical mapping of the CO2 release plume that is difficult to obtain using more conventional techniques. The figures show the nature and quality of the data from one of the locations. Details concerning instrument performance, systematics, calibration, and data processing will be discussed. Fig1: Time chart of CO2 concentration and isotope ratio δ13C from one of 13 sample inlet locations at ZERT release field, July, 2009.
Fig2: Keeling plot of data from Fig1 illustrating the two source mixing of soil (-27 ‰) and fossil (-56 ‰) CO2 with background air.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFM.U12B..04M
- Keywords:
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- 0394 ATMOSPHERIC COMPOSITION AND STRUCTURE / Instruments and techniques;
- 0454 BIOGEOSCIENCES / Isotopic composition and chemistry;
- 3394 ATMOSPHERIC PROCESSES / Instruments and techniques;
- 9805 GENERAL OR MISCELLANEOUS / Instruments useful in three or more fields