The AMeDAS(Automated Meteorological Data Acquisition System) consits of automatic observation facilities operated by the Japan Meteorological Agency. 840 AMeDAS observation sites, located at intervals of about 21 km all over Japan, observe four meteorological elements: air temperature, wind direction and speed, precipitation and sunshine duration. Those data are monitored every hour through a telecommunications network.
AMeDAS data have been utilized in various research projects on meteorological phenomena, guidance for daily forecasts and for the parameterization of boundary layers for numerical weather prediction models. More than 20 years have passed since AMeDAS was established in 1974, and the accumulation of those data can be expected to form a statistical basis for further meteorological research. Thus, we began investigation of AMeDAS data from a statistical point of view.
In this study, we plan to systematically utilize all of these accumulated data for various kinds of research, such as meso-scale meteorology, effects of topography on meteorological phenomena, and parameterization of boundary layers of sub grid scales. Adaptation of these data for investigations into local climate changes were also studied.
AMeDAS data are classified carefully according to dominant meso scale meteorological phenomena and various kinds of meteorological conditions, and studied in connection with related synoptic scale phenomena represented by grid point data obtained from objective analysis of the NWP or by other means.
As the first stage of this study, the time differentials of air temperature were investigated in relation to sunshine duration, surface wind, and equivalent soil moisture content calculated from a tank model. Seasonal changes related to ground use were also investigated. We report in this paper some of our results for the parameterization of boundary layers on a sub grid scale.