12:00 PM - 12:15 PM
[AAS21-17] Atmospheric methane measurement by open-path laser methane instrument at paddy fields in India
Keywords:methane, open-path laser spectroscopy, paddy field, India
The developed measurement system consists of gas sensor, power supply, data logger, remote control instruments and telecommunication equipment. The methane gas sensor is used a laser methane measurement instrument (LaserMethane, ANRITSU CORPORATION) which is a portable detector with low electric consumption, easy maintenance, and outdoor use. Remote sensing of methane is accomplished by means of infrared absorption spectroscopy with near-IR diode laser using reflected light from a reflector located at several tens meters away from the detector. High sensitivity is achieved by the second-harmonic detection of wavelength modulation spectroscopy. It can quickly and selectively detect the integral methane concentration on the optical path of the laser beam. To measure the methane concentration at paddy field in India, the methane measurement system was installed at rural area (Sonepat, Haryanea) on the north of Delhi and has been operated since the winter of 2014. The air sampling along with our measurement has been carried out once a weak currently. The methane concentration from the laser instrument can be corrected with the more precise value of the sampled air. To establish how to correct the data and calibrate the system, we performed both of laboratory experiment and field measurement. We will present about the development of the open-path laser methane measurement system and the recent results of field measurement in India.