| Based on the Beijing 325 m meteorological tower, O3, NOx concentration and meteorological parameters in urban atmospheric boundary-layer were measured from July to August, 2000 and 2002.First, The variations of O3 concentration on difference levels were discussed, and the relations between O3 concentration and [NO2/NO] ratio were studied. It indicate that the variations of O3 concentration exist remarkably different on difference levels. Contrasted with the high level, the clearly daily variation is shown, and difference value is large day and night in the low level observations. Depended on our fitting analysis, It is also found that the mean accumulative time of ozone pollution (the damage for people health criterion) in summer is 3.6 hours per day. It is concluded that the ozone pollution in summer of Beijing is getting more heavier than before.Second, the relation between O3 concentration and [NO2/NO] ratio is linear during the daytime of 10:00-16:00 (local time), however, which is greatly affected by meteorological background. At 8m and 120m in daytime ,the rate of ozone concentration and NO2/NO took on remarkably linear relation if it shined , it reaches simple stabile photochemistry state,The rate at 8m was 2-4,and 3-5 at 120m ,the data we got and stimulate result of numerical model were not always meet .We found farther that wind speed did little to the rate of ozone concentration and NO3/NO reaching photochemistrystabile state,while single wind direction did good to the rate of ozone concentration and NO2/NO reaching photochemistry stabile state.Besides, the stability (Ri) were in neutral state mostly and the variation of Ri were small in lower levels, and it were in non-stability largely and the variation of RI were large in higher levels. The variations of ozone fluxes both displayed single-peaks in difference levels. It is also found that the pollution of ozone was most serious in 120m in daytime, because of the progenitor of O3 and local photochemistry reaction. |
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