Forecasting of Atmospheric Stagnation in the Kyoto Basin

Abstract

The Kyoto basin is surrounded on three sides by mountains about 300-500m high. So, in winter, temperature inversion is apt to develop in this basin. Sea breezes do not come directly from the sea. In Kyoto, there are not such large factories; however the concentration of air pollution increases as much as that of a big industrial city, especially on winter mornings. We observed the temperature distribution in the vertical north-south cross-section in the Kyoto basin using thermister thermometer recorder mounted on a small plane. After analysing the vertical distributions of temperature and wind, we find that the difference between minimum temperatures on the top of Mt. Hiei and at the bed of the Kyoto basin is a good indicater of the air pollution in the Kyoto basin. We examined the variation of the concentration of pollutants, the index of stability described above and the height of the 500 mb surface over Japan for winter days over two years. We found a high correlation between these elements. With these facts, we discussed the possibility of forecasting atmospheric stagnation in the Kyoto basin.