Kohei Arai and Yuichi Sarusawa
The observatories of the Ariake Sea reported that the transparency was increased in recent years. The time series analysis of transparency is considered important to probe the feature of the sea. No data, however, can be used to account for the entire sea, since the data of the observatories is based on dots. This study estimated the turbidity of the entire sea and the secular variation with MODIS data. The experiment with the regression analysis of particular wavelength suggested that the turbidity of the entire sea decreased. Thus, the transparency appears to increase.