| Research Abstract |
Utilizing the hourly data for the years 1983-93 supplied from the Environmental Affairs Bureau of Nagoya-shi and the Department of Environment of Aichi-ken, we analyzed the spatial distribution of the atmospheric methane in Nagoya and its surrounding region. In the spatial distribution of methane concentration we found a characteristic pattern with several maxima, and examined the diurnal, seasonal (or annual) variations and long-term trend. In the present work we made supplimental observations in several days of 1996-97 early winter within and around the maximum concentration area expected from the analysis of the official network data, and confirmed our model of the spatial distribution of methane. For the next step of the study we made a preliminary observation at the Nagoya-TV Tower ; and we found a characteristic variation in the daytime and just after the sunset of the height distribution of methane, which depends on the mean wind.
The above findings are deduced from the limited data, i.e.mostly at surface observatinal sites. Our preliminary studies, however, suggest that comprehensive 3-dimensional observations will clarify interesting relationships between the spatial distribution of the methane and meteorological conditions in the urban and its surrounding area.
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