Continuous in-situ methane measurements at paddy fields in a rural area of India with poor electric infrastructure, using a low-cost instrument based on open-path near-IR laser absorption spectroscopy

Wednesday, 16 December 2015
Poster Hall (Moscone South)
Takehiro Hidemori1, Yutaka Matsumi2, Tomoki Nakayama2, Masahiro Kawasaki1, Hiroshi Sasago1, Kenshi Takahashi3, Ryoichi Imasu4, Wataru Takeuchi5, Minako Adachi6, Toshinobu Machida7, Yukio Terao7, Shohei Nomura8, Surendra Kumar Dhaka9 and Jagmohan Singh10, (1)Nagoya university, Solar-Terrestrial Environment Laboratory, Nagoya, Japan, (2)Nagoya University, Nagoya, Japan, (3)Kyoto University, Kyoto, Japan, (4)University of Tokyo, Bunkyo-ku, Japan, (5)University of Tokyo, Institute of Industrial Science, Bunkyo-ku, Japan, (6)University of Tsukuba, Tsukuba, Japan, (7)NIES National Institute of Environmental Studies, Ibaraki, Japan, (8)National Institute for Environmental Studies, Tsukuba, Japan, (9)Radio and Atmospheric Physics Lab., Rajdhani College, University of Delhi, Delhi, India, (10)Jamia Millia Islamia, New Delhi, India
In southeast and south Asia, the previous satellite observations suggest that the methane emission from rice paddies is significant and important source of methane during rainy season. Since it is difficult to measure methane stably and continuously at rural areas such as the paddy fields in terms of infrastructures and maintenances, there are large uncertainties in quantitative estimation of methane emission in these areas and there are needs for more certification between satellite and ground based measurements. To measure methane concentrations continuously at difficult situations such as the center of paddy fields and wetlands, we developed the continuous in-situ measurement system, not to look for your lost keys under the streetlight.

The methane gas sensor is used an open-path laser based measurement instrument (LaserMethane, ANRITSU CORPORATION), which can quickly and selectively detect average methane concentrations on the optical path of the laser beam. The developed system has the power supply and telecommunication system to run the laser gas sensor in rural areas with poor electricity infrastructure.

The methane measurement system was installed at paddy fields of Sonepat, Haryana on the north of Delhi in India and has been operated from the end of 2014. The air sampling along with our measurement has been carried out once a week during daytime to calibrate the laser instrument. We found that the seasonal variation of methane concentrations was different from the satellite observations and there were significant diurnal variations, which it was difficult to detect from occasional air samplings. We will present details of the measurement system and recent results of continuous methane measurements in India.