Using meteorological data and emission data gotten in the Ise Bay District on 4-5, Aug., 1977, a numerical simulation of photochemical air pollution was conducted. The wind field was represented through an interpolation of observed data. Diffusion and photochemical reaction were computed respectively with the diffusion equation and simplified chemical equations. The simulation could represent for these days that developing high O3 masses drifted northeasterly by the sea breeze which arose in the eastern or southern part of Nagoya around Atsumi bay. Computational error remained below the tolerable level in most of the object area. However, the simulation overestimated distinctly at the limited part of the Chita peninsula late on the morning of 5 th. As a cause of the deviation, it is supposed that local western sea breeze continued in this period and pollutants were tossed into higher layers over the region, because topographic and thermal convection affected the wind greatly across the peninsula. These thermal plumes could not be represented in the interpolated wind field. The probability of the above-mentioned cause was supported by two-dimensional test computation of the western sea breeze, including thermal and topographic effect.
This paper provides a complete set of data on the monthly fall rate of tritium (HTO) in precipitation at the Meteorological Research Institute (Tokyo and Tsukuba) from August 1963 to December 1980. The concentration of tritium ranged from 5500 pCi/dm3 in March 1964 to 5 pCi/dm3 in November 1979. The highest frequency of appearance of the maximum and the minimum is seen June and November, respectively. The trend of gradual decrease from 1963 to 1967, which gives the apparent residence time of tritium (23 months), has been disturbed by the series of Chinese thermonuclear tests. The amount of tritium produced by the 1961-1962 testing is estimated to be 1900 MCi based on the cumulative amount of tritium and 90Sr in Tokyo and the ratio of the deposition between the two nuclides in Tokyo and the Northern Hemisphere.
Results of study on the chloride concentration in the surface air at Tsukuba Science City, Japan, are here reported. The chloride concentration in the airborne particles was high in the winter time, ranging from 0.2 to 16 μg m-3. In the other seasons, it ranged from 0.2 to 3 μg m-3 with an average value of 1.2 μg m-3. The size distribution of chloride particles revealed that in the winter time, chloride is much concentrated in small particles. The high concentration of chloride in winter also coincided with a day of low wind speed with a near the surface inversion layer. A good correlation was found between the concentration of chloride and the total carbon in airborne dust, whereas no relation was found between sodium and chloride. It was concluded that the high concentration of chloride in the surface air in winter was due to the combined effect of local pollution originating from the burning of agricultural waste and the prevailing near surface inversion layer.
We studied the utility of SASS (Seasat-A scatterometer system) wind data observed during 3 months in the summer season of 1978. Results were reported in the Annual Research Report, 1981 for the Meteorological Research Institute. The author selected one wind using streamline analysis for four winds and analyzed the surface wind characteristics of the Typhoon. Many lower weak spiral cloud bands observed by GMS VIS agreed with a flow pattern of winds selected from SASS data. A general flow at the 900 m height level translated wind (using Blackadar relation. 1962) and the Typhoon circulation wind were divided clearly in the case of shallow storms, but were not divided clearly in moderate Typhoons. Sharp spiral cloud bands corresponded well with the confluence wind zone. The center calculated by RMSE (root mean square error) method using SASS winds agreed well with the position gained by Reconnaissance flight and other methods.