JAL 1993 - 2000

Brief description

In April 1993, JAL Foundation set up a joint atmospheric observation project in cooperation with Japan Airlines and the Meteorological Agency, under the support of the Ministry of Land, Infrastrucure and Transport. For this project, a special device for collecting air samples from the upper troposphere was developed. This device has been installed on Japan Airlines regularly flying airliners between Australia and Japan. After the landing of an airliner at Narita airport, the device is brought into the Research Institute of the Meteorological Agency, where the sample is analyzed in order to determine the concentration of greenhouse effect gases in the upper troposphere. This twice per month atmospheric observation revealed that,

1. The seasonal changes of the carbon dioxide due to photosynthesis occurring at the ground surface influence very much the upper air, and the rate of increase correlates well with all results obtained from ground surface and ocean surface observation stations around the world, then, the carbon dioxide generated mainly at the ground surface of middle and high latitude northern hemisphere is carried to the upper troposphere.

2. The carbon dioxide generated at the ground surface of middle and high latitude northern hemisphere is carried to the southern hemisphere along with the atmospheric movement, such as wind, convection, etc., and part of the carbon dioxide is carried to much high altitude, and after once carried to the middle and high latitude southern hemisphere along with the atmospheric movement at very high altitude, it is carried toward the equator (northern movement) at the relatively low altitude.

3. Carbon monoxide generated by extensive bush fires in South East Asia together with strong El-Nino phenomena in 1997, was carried to extensive high altitude along with the strong convection, and influenced the atmospheric composition at high altitude.

Special remarks concerning ETHmeg database content

A recently revised and recalibrated version of the JAL data is included in the TRADEOFF database.
Note: 12 samples were taken on each flight at 30 min time intervals. The sampling time (the time required to fill a flask to 40 psia was 10 s. These "raw" values are stored in the database without any further averaging or processing.

Overview of measurement techniques and uncertainties

References

- Matsueda and Inoue, Atmospheric Environment, 30, pp. 1647-1655, 1996 (for CO2, CH4)
- Matsueda et al., J. Geophys. Res., 103, pp. 19,093-19,110, 1998 (for CO)