[A-AS06] 大気化学

[AAS06-P03] Working standard gas saving system for in-situ CO₂ and CH₄ measurements and calculation method for concentrations and uncertainty.

*Motoki Sasakawa¹、Noritsugu Tsuda²、Toshinobu Machida¹、Mikhail Arshinov³、Davidov Denis³、Alexandrov Fofonov³ (1.NIES National Institute of Environmental Studies、2.Global Environmental Forum、3.Institute of Atmospheric Optics, Russian Academy of Sciences, Siberian Branch, Russia)

キーワード：Carbon dioxide, Methane, Siberia, in-situ measurement, CRDS

Continuous measurements of CO₂ and CH₄ concentration have been carried out using a tower network in Siberia (JR-STATION: Japan-Russia Siberian Tall Tower Inland Observation Network) to study the spatial and temporal variations of CO₂ and CH₄ and estimate the distribution of the flux over this vast area (Sasakawa et al., 2010, 2012, 2013) where only a few atmospheric investigations had been made. Transport of working standard gases to remote sites is a significant issue. Thus, to reduce the consumption of the gases, Watai et al. (2010) developed a system that utilizes in-situ air as sub-working standard gas to track the baseline drift of an NDIR. The calibrations using the working standard gases were carried out twice a day. Watai et al. (2010) installed the system at the first tower site in West Siberia (Berezorechka). We modified the working gas saving system and further added a CH₄ sensor (Suto et al., 2010), then expanded the tower network. We evaluated the uncertainty of the concentrations obtained from this modified system. From the year of 2015, we installed a Cavity Ring-Down Spectroscopy (CRDS; Picarro inc.) at Karasevoe, Demyanskoe, and Noyabrsk. We thus validate the recent data with the data by the CRDSs.

References
Sasakawa, M. et al., Tellus 62B, 403-416, 2010.
Sasakawa, M. et al., Tellus 64B, doi:10.3402/tellusb.v64i0.17514, 2012.
Sasakawa, M. et al., J. Geophys. Res. 118, 1-10, doi:10.1002/jgrd.50755, 2013.
Suto, H. et al., J. Atmos. Ocean. Tech. 27, 1175-1184, 2010.
Watai, T. et al., Atmos. Ocean. Tech. 27, 843-855, 2010.