Aircraft measurements of carbon dioxide and methane for the calibration of ground-based high-resolution Fourier Transform Spectrometers and a comparison to GOSAT data measured over Tsukuba and Moshiri
- 1National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan
- 2Solar-Terrestrial Environment Laboratory, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan
- 3Meteorological Research Institute, 1-1 Nagamine, Tsukuba, Ibaraki, 305-0052, Japan
- 4California Institute of Technology, Pasadena, CA, 91125-2100, USA
- 5Japan Aerospace Exploration Agency Earth Observation Research Center, 2-1-1 Sengen, Tsukuba, Ibaraki, 305-8505, Japan
- *now at: Japan Aerospace Exploration Agency Earth Observation Research Center, 2-1-1 Sengen, Tsukuba, Ibaraki, 305-8505, Japan
- **now at: Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka kita-ku, Okayama, 700-8530, Japan
Abstract. Aircraft measurements of carbon dioxide and methane over Tsukuba (36.05° N, 140.12° E) (February 2010) and Moshiri (44.36° N, 142.26° E) (August 2009) were made to calibrate ground-based high-resolution Fourier Transform Spectrometers (g-b FTSs) and to compare with the Greenhouse gases Observing SATellite (GOSAT). The aircraft measurements over Tsukuba in February 2010 were successful in synchronizing with both the g-b FTS and GOSAT for the first time. Airborne in situ and flask-sampling instruments were mounted on the aircraft, and measurements were carried out between altitudes of 0.5 and 7 km to obtain vertical profiles of carbon dioxide (CO2), methane (CH4), and other gaseous species.
By comparing the g-b FTS measurements with the airborne measurements, the column-averaged dry air mole fractions of CO2 (XCO2) and CH4 (XCH4) retrieved from the g-b FTS measurements at Tsukuba were biased low by 0.33 ± 0.11% for XCO2 and 0.69 ± 0.29% for XCH4.
The g-b FTS values at Moshiri were biased low by 1.24% for XCO2 and 2.11% for XCH4. The GOSAT data show biases that are 3.1% ± 1.7% lower for XCO2 and 2.5% ± 0.8% lower for XCH4 than the aircraft measurements obtained over Tsukuba.