北京地面紫外辐射与空气污染的关系研究

Relationship Between Surface UV Radiation and Air Pollution in Beijing

基于北京城区太阳辐射和污染气体观测资料,运用TUV4.4辐射传输模型,研究了城市大气中太阳紫外辐射与空气污染的相互关系.结果表明,臭氧总量平均为329DU,并呈冬春季较高,夏秋季较低的季节变化规律,到达地面的紫外辐射呈现相反的变化趋势;受城区大气污染的影响,地面处的紫外辐射量大幅减少(最大50%),且在夏季波动较大;云和污染物对紫外辐射的影响要大于总辐射,紫外辐射衰减约为总辐射衰减的2倍;城市低层大气中O3和NOx浓度的增加是造成紫外辐射衰减的重要原因,午后O3浓度与紫外辐射衰减相关系数为0.70.

Based on the data of solar radiation and air pollutants collected in Beijing,the relationship between surface ultraviolet（UV） radiation and the content of air pollutants were analyzed,using the radiative transfer model TUV4.4（Tropospheric Ultraviolet Visible）.The results show that average total ozone content is 329 DU and higher in winter and spring,lower in summer and autumn.The inverse relationship exists between ground level UV radiation and total ozone content.This study also shows that a substantial reduction（up to 50%） in the UV radiation on days with high levels of air pollution.Larger fluctuations are found in UV radiation in the summer.The effects of clouds and air pollution on UV are higher than on total solar radiation,and the reduction in UV is about twice as large as the total solar radiation values.Strong reduction in the UV radiation reaching the ground is associated with the increase of tropospheric ozone and nitrogen oxides in Beijing.The correlation coefficient between ozone concentration and decrease in UV radiation is 0.70 in the early afternoon.