Latitudinal distribution of methane as observed by IMG sensor aboard ADEOS satellite

Interferometric Monitor for Greenhouse gases aboard advanced earth observing satellite (ADEOS) is a Fourier transform type spectrometer which had been developed for measuring greenhouse gases in the atmosphere, particularly in the troposphere. It had been operated for about 7 months from November 1996 up to the end of the life time of the ADEOS on June 1997. During the operational period IMG had measured over 138000 terrestrial thermal emission spectra of which the signal to noise ratio is sufficient for retrieving atmospheric parameters such as temperature and gas concentrations. As most of the data had been obtained during the 4-days operational period which had been scheduled twice in each system request period, we have obtained about 15 global data sets of the IMG data during the whole IMG operational period. A cloud detection and correction method which was based on the analysis of the initially retrieved temperature profiles were presented. Using the cloud correction method, latitudinal distribution of methane was preliminary analyzed and an example of the result was shown.