基于卫星数据研究兰州市NO2时空分布特征以及冬季NOx排放通量

搭载在EOS AURA卫星上的OMI探测器由于其较高时空分辨率在大气痕量气体(O3,NO2,SO2)探测中得到广泛应用.利用2010~2012年OMI NO2柱浓度数据产品重构了兰州市以及周边地区NO2柱浓度分布,分析了其时空变化特征,并利用西南风场下NO2空间分布特征采用拟合方法研究了NOx冬季排放通量以及寿命.研究表明,NO2柱浓度空间分布呈现以兰州市为中心,浓度向四周扩散的特征;兰州市NO2柱浓度的年变化特征为12月达到最大浓度,8月达到最小浓度;2010~2012年NO2寿命分别为10.6,9.9,9.1h,NOx冬季排放通量分别为175.3, 183.7,179.9mol/s.其排放通量与兰州环境公报提供的氮氧化物排放通量数量级之间具有较好的一致性,说明利用卫星数据估算兰州的NOx通量方法的有效性.

Research on the spatial/temporal patterns of NO2 concentration and NOx emissions of Lanzhou by applying satellite data

OMI (Ozone Monitoring Instrument) on abroad the EOS AURA satellite is widely used to observe the trace gases (O3, NO2, SO2) for its high spatial and temporal resolution. The distribution of NO2 column concentration over Lanzhou was reconstructed using data from OMI database (2010~2012), following the analysis of variation of spatial and temporal patterns, and the estimation of NOx emissions when considering the distribution of NO2 concentration under south-western wind. The results shown that: in the spatial pattern, the NO2 column concentration at the center of Lanzhou City was the highest, and the concentration of NO2 decreased with the distance from the center. In the time pattern, the NO2 column concentration of Lanzhou City reached the highest value in December, and the lowest value in August. The lifetime of NO2 in Lanzhou during wintertime from 2010 to 2012 was about 10.6, 9.9, 9.1h respectively, and the NOx emission rate was about 175.3, 183.7, 179.9mol/s respectively. The emission rate calculated matched the data provided by the “Lanzhou Environment Bulletin”, which indicated that analyzing the distribution of NO2 under special wind direction provides a feasible way to estimate the emissions of NOx.