Four main projects on the atmospheric science as shown in bellow, which I have studied in Osaka Prefecture University for 28 years from 1972, are summarized.
1) Development of continuous determination methods for low concentration levels of air pollutants by using chemiluminescence method.
2) Transformation of air pollutants during the phase change such as freezing and evaporation.
3) Materials damage as an index of air pollution impact which synergistically caused by complicated multi-pollutants.
4) Development of the sonolytical new treatment process of toxic organic pollutants.

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The recent developments of numerical models used to analyze the atmospheric environment are summarized from the activities of the Modeling/Field-Data-Analysis Subcommittee, Japan Society for Atmospheric Environment, which operated from 1996 to 1998. Specific scales have been developed to define the particular characteristics of air pollution, and numerical models have been developed along the same lines. The development of these models is introduced from a micro-to a regional scale.

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The lateral component of atmospheric turbulence v contains a low frequency component. Therefore horizontal plume spread increases with observation time. To simulate wide plume spread in a wind tunnel, the oscillating wing method was developed, in our previous study. In this method, low frequency turbulence is generated with the random oscillating motion of a wing row set at the inlet of a test section. One hour average plume spread pattern in a wind tunnel can be reproduced. In this study, artificially generated turbulence was examined for the presence of any unnatural features by comparing the results of a conventional wind tunnel experiment with atmospheric boundary layer data. Vertical distribution of average wind velocity, turbulence intensity and turbulence scales were essentially the same as atmospheric parameters. V component coherence functions between two points in a lateral direction were found to differ from those for natural wind. The vertical distribution of v-component correlation coefficients was found to be greater than that of natural wind or that by the conventional method.

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Atmospheric turbulence contains many components within a low frequency range, and consequently plume spread varies with the time of observation, and the direction of the plume axis changes at the start of and during this time. One-hour average plume spread and concentration distribution were simulated in a wind tunnel, in a previous study, using the oscillating wing method. An experimental method for simulating plume meander was proposed in the present study. The plume axis was fixed to the wind tunnel axis. In the v component spectrum, high frequency range which is a determinant of instantaneous plume spread and meander was remained, but low frequency range which governs the direction of the long time average plume axis was deleted. V component turbulence intensity and characteristic turbulence length were noted to be in agreement with atmospheric turbulence over a period of one hour. In a plume diffusion test under those conditions, long time average plume spread was the same as that determined from field observation. Instantaneous plume spread had the same value as calculated from the conventional experimental method. The concentration fluctuation was twice that by the conventional method, and the peak factor for this parameter was 3.3 times as much, in which are agreement with the results for a fluctuating plume model by Gifford.

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We collected seeds of Solidago virgaurea plants growing at different altitudes in the Mt. Hakusan area of Japan and cultivated them in a naturally-lit green house. Three-week-old seedlings were irradiated with supplemental UV-B for 12 h each day for 1 and 2 weeks. After a week of irradiation seedlings from the higher altitude population at Oh-nanjiho (ON) had accumulated more anthocyanins than those from the lower altitude population at Bettoh-deai (BD). Levels of anthocyanins in the ON seedlings were highly correlated with the dose of UV-B radiation and this correlation was also observed after 2 weeks. The growth of third leaves was retarded by UV-B radiation in both populations. The extent of growth retardation in third leaves was correlated with the dose of UV-B radiation in both populations. However, no significant difference in the extent of leaf area growth was observed between the ON and BD populations. The increase in plant fresh weight was extensively inhibited in the ON seedlings after 1 week of UV-B radiation. The inhibition recovered to the levels of those in the BD population following a week of irradiation. These results indicate that the two populations respond differently to supplementary UV-B radiation during the fi rst week. Because flavonoids such as anthocyanins play an important role in protection against UV-B radiation in many plants, populations growing at higher altitudes may be better able to adapt to increased global levels of UV-B radiation.

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To evaluate dry deposition which is indispensable in estimating the effect of acid deposition on forest ecosystems and cultural properties, a 4-stage filter pack method (F₀-F₃), a technique to determine concentrations of air pollutants, was modified and technically evaluated. Usinga 0.8μm polytetrafluoroethylene filter as a first stage (F₀), gaseous components can be separated completely from suspended particulate matters. Polyamide filter used as a second stage (F₁) selectively collected HNO₃, and to a lesser degreee also SO₂, HCI and NH₃. K2CO₃ impregnated cellulose filters as a third stage (F₂) and H₃PO₄ impregnated filters as a fourth stage (F₃) can collect SO₂ and HCI, and NH₃, respectively. From these results, it is considered that SO₂ and HCI should be calculated from the total amount of components on F₁ and F₂ filters, and NH₃ from that on F₁ and F₃. A 4-stage filter pack method can be useful for dry deposition monitoring, when carried out according to detailed technical standards for measurement to maintain precision.

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