Summary of the Final Report of Research Results1) Title of the proposed research
An instrument prototype for column CO2, CH4 and N2O using direct solar flux
2) Principal Investigator (PI) and Co-Investigators (Co-Is)
PI:
Dr. Masahiro Kawasaki
Co-I:
Dr. Akihiro Yabushita
Dr. Gen Inoue
3) PI’s affiliation
Kyoto University4)

Summary of the Final Report of Research Results
Remotely operable compact instruments for measuring atmospheric greenhouse gas column

densities have been developed in two independent systems: one utilizing a grating based desktop
optical spectrum analyzer (OSA) with a resolution enough to resolve rotational lines of CO2 and CH4
in the regions of 1569–1575 and 1670–1680 nm, respectively; the other is an application of an
optical fiber Fabry-Perot interferometer (FFPI) to obtain the CO2 column density, which is inspiredby a solid-state FFPI reported by Wilson et al. (Wilson, E. L., Georgieva, E. M., and Heaps, W.
S.: Development of a Fabry-Perot interferometer for ultra-precise measurements of column CO2,Meas. Sci. Technol., 18, 1495, 2007). Direct sunlight was collimated via a small telescope installed
on a portable sun tracker and then transmitted through an optical fiber into the OSA or the FFPI for
optical analysis.

The practical usefulness of the OSA instrument was examined in two separate
measurement campaigns. The first comparison involved operating the OSA in parallelwith a high resolution Fourier transform spectrometer. The second comparison is acalibration against aircraft CO2 profiles in situ during a GOSAT validation campaign.
The xCO2 values in the campaign are in excellent agreement with the integrated
aircraft profiles. Due to its portability, the FFPI instruments were set in central
Kalimantan, Indonesia, as a part of measurement reporting validation MRV activities
for CO2 emission reduction during the forest/peatland fire season. In this campaign, twosets of the FFPI instruments were deployed parallel to the predominant wind direction
at two cities, respectively. Two months of column data were automatically obtained. Alarge increase in xCO2 was detected, which was caused by large scale forest andpeatland fires between the two cities.
Field campaigns have shown that both instruments are promising technologies formeasuring atmospheric CO2 and CH4 column densities at surface sites. Due to theirsmaller size and lower cost these instruments are expected to provide a supplemental
measuring system to the existing surface site network. We are working to establish an
operating structure that allows effective monitoring, especially in situations andregions where there has not yet been sufficient data collection to quantitatively assess
the greenhouse gas emissions.
5) List of publications relating to the proposed research
1. N. Kobayashi, G. Inoue, M. Kawasaki, H. Yoshioka, M. Minomura, I. Murata, T. Nagahama, Y.
Matsumi, T. Tanaka, I. Morino and T. Ibuki, “Remotely operable compact instruments formeasuring atmospheric CO2 column densities at surface monitoring sites”, Atm. Measure. Tech.
3 (4) 1103-1112 (2010)
2. M. Kawasaki, H. Yoshioka, N. B. Jones, R. Macatangay, D. W. T. Griffith, S.
Kawakami, H. Ohyama, T. Tanaka, I. Morino, O. Uchino, and T. Ibuki “Usability ofoptical spectrum analyzer in measuring atmospheric CO2 and CH4 column densities:
substantiation with FTS and aircraft profiles in situ”, Atmos. Meas. Tech., 5,2593–2600 (2012)
3. Masahiro Kawasaki, Masafumi Ohashi and Gen Inoue, “Carbon emission measurement by aportable CO2 column spectrometer”, SPIE Newsroom, 10.1117/2.1201313.004659 (2013)