113 ADEOS衛星搭載IMGセンサーにより観測されたメタンと一酸化炭素の全球分布

抄録

Interferometric Monitor for Greenhouse gases (IMG) aboard Advanced Earth Observing Satellite (ADEOS) is a Fourier Transform type Spectrometer (FTS) which was developed by Japanese Ministry of International Trade and Industry (MITI) for measuring greenhouse gases in the atmosphere. It had been operated for about 7 months from November 1996 to the end of the satellite life time in June 1997. During the operational period IMG has measured over 138000 terrestrial thermal emission spectra of which the signal to nose ratio is sufficient for retrieving atmospheric parameters such as temperature and gas concentrations. Preliminary results from the IMG retrieval analyses showed that there were some high concentration areas of methane and carbon monoxide in the northern hemisphere and around tropical region, respectively. In these analyses a cloud screening and correction method which was based on the initially retrieved temperature profile analysis was used to retrieve the gas concentrations. However, the results might be strongly affected by cloud contamination effects, because the loud screening method was not effective enough for the data observed over high latitude regions. It is very important to validate these retrieved data using directly sampled gas concentration data, and also important is to develop a more effective cloud detection method using satellite imagery data such as OCTS data.