Continuous measurements for isotopic ratios of CO2(δ13C, δ18O), water vapor(δD, and δ18O-H2O) in the urban area using laser IR spectroscopic techniques and their analysis with other pollutant species(CO, NOx)
Abstract
The concentration of CO2 has been increasing from a range of 275 to 285 ppmv in the previous industrial period to about 400 ppmv in 2012. IPCC reported that CO2 has the most effects on positive radiation forcing (IPCC 2007). The accurate estimation of the CO2 emission and loss flux are necessary to improve the prediction of the radiation forcing and atmospheric environment. In the urban area, CO2 concentration varies due to the anthropogenic and biogenic emission and advection. We conducted the continuous measurement of CO2 concentration and stable isotope ratio of CO2 (δ13C and δ18O) using the laser isotope spectrometer in Nagoya, Japan during two weeks of winter 2011 and summer 2012. CO2 isotope laser spectrometer can continuously measureδ13, δ18O in high time resolution (10 seconds). We also measured CO, NOx and H2O concentration, and stable isotope ratio of H2O (δD and δ18O-H2O). CO2 sources in summer and winter were identified from the Keeling plot analysis of the CO2 isotope ratio (δ13C and δ18O) and relationship between CO and CO2 concentration variation. The ratio of CO concentration to CO2 concentration shows the contribution of the fossil fuel combustion or biogenic respiration. Lower ratio of CO to CO2 concentration was due to the biogenic respiration because few CO emits from the biogenic respiration. We will discuss the seasonal variation of CO2 source from the analysis of CO2 isotope ratio and CO2 concentration comparing with CO and NOx concentration variation.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFM.A53E0218Y
- Keywords:
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- 0345 ATMOSPHERIC COMPOSITION AND STRUCTURE Pollution: urban and regional;
- 0365 ATMOSPHERIC COMPOSITION AND STRUCTURE Troposphere: composition and chemistry;
- 0322 ATMOSPHERIC COMPOSITION AND STRUCTURE Constituent sources and sinks