基于OMI卫星数据的城市对流层NO2变化趋势研究

Study on Tropospheric NO2 Change Trend in Cities Using OMI Satellite Data

利用OMNO2全球产品卫星遥感资料研究科技城市北京、交通城市黄骅港、旅游城市三亚、特区城市深圳和工业城市抚顺的NO2月平均变化情况。通过Beat软件和IDL联合编程对该产品进行处理,得到各城市对流层NO2垂直柱密度的月平均值;对各城市2004年10月至2007年10月的NO2月平均变化进行线性正弦模型模拟,得到月平均变化趋势和月增长率,并评价变化趋势的精度。结果显示,各城市在冬季NO2对流层垂直柱密度较大,夏季较小,季节性循环明显。北京、黄骅港、三亚、抚顺在这段时间NO2总体呈增加趋势,从大到小依次是:抚顺、北京、黄骅港和三亚,深圳呈减少趋势。根据趋势显著性判别准则,各城市的NO2月平均变化均显著。另外相对于2004年10月,月相对增长率从大到小依次是抚顺、三亚、黄骅港、北京、深圳,其中深圳的NO2呈现负增长。

The results ot monthly average tropospheric NO2 change trends over Beijing（technological city）, Huanghuagang（traffic city）, Sanya（tour city）, Shenzhen（special city） and Fushun （industrial city） are presented, on the basis of OMNO2 global product. Monthly average tropospheric NO2 vertical column densities are acquired from OMNO2 global product using Beat tools and IDL. A linear sine model is used to fit these time series from October 2004 to October 2007 in these cities. Change trend and growth rate （Oct. 2004 as reference） of monthly average tropospheric NOz vertical column density is gained. Precision of change trend is also estimated. The result shows that in these cities a seasonal NO2 maximum is found during wintertime, the minimum is found during summertime. Seasonal cycle of the NOz vertical column density is very clear. The change trends over Beiiing, Huanghuagang, Sanya and Fushun are increased, and their sequence from maximum to minimum is Fushun, Beijing, Huanghuagang and Sanya. But the change trend over Shenzhen is decreased. According to a decision rule for significance of trend, the change trend over every city is real. In addition, the sequence of monthly growth rate from maximum to minimum referring Oct. 2004 is Fushun, Sanya, Huanghuagang, Beijing and Shenzhem Among them, growth rate over Shenzhen is negative. This study confirms finally that remote sensing has a high application value in monitoring air pollution of city, and can overcome the shortcomings of traditional methods.