基于OMI数据的成渝城市群对流层NO2浓度遥感监测

利用Aura卫星的OMI（Ozone Monitoring Instrument）传感器最新版对流层NO2垂直柱浓度数据产品，结合线性拟合、趋势分析和空间自相关分析等方法，系统分析了2005~2017年成渝城市群对流层NO2垂直柱浓度的时空特征及变化趋势。结果表明：OMI对流层NO2柱浓度数据与成渝城市群NO2地面监测数据变化趋势基本一致，且存在良好的相关性；时间上，2005~2012年NO2年均柱浓度增加明显，增幅达52.38%，2012年后呈下降趋势。NO2柱浓度季节变化明显，浓度水平基本为：冬季>秋季>春季>夏季。NO2柱浓度月均值具有类似于正弦函数的周期性，1年一个周期，低值出现在每年的7、8月，高值出现在11、12和1月；空间上，经济较发达地区的NO2浓度大于经济欠发达地区。2005~2012年99.58%的区域NO2浓度上升,2012~2017年80.50%的区域NO2下降，但是成渝城市群边缘的山区NO2浓度依然呈增长趋势。成都、重庆对流层NO2柱浓度具有明显的局部空间正相关特性。

Remote Sensing Monitoring of Tropospheric NO2 Density in Chengdu- Chongqing Urban Agglomeration Based on OMI Data

This paper systematically analyzes the characteristics of spatial and temporal distribution of NO2 vertical column density from 2005 to 2017 in Chengdu-Chongqing Urban Agglomeration (CCUA). The tropospheric NO2 vertical column density data were from the latest version of OMI (Ozone Monitoring Instrument) sensor of Aura satellite. The techniques of linear fitting, trend analysis and spatial autocorrelation analysis were used in this paper. The results showed that in CCUA there was reasonable correlation between the ground monitoring NO2 column density and the data from OMI sensor, and their variation trends were basically consistent. From 2005 to 2012, the annual NO2 column density increased about 52.38%, and it decreased after 2012, and for the density level in four seasons, winter > autumn > spring > summer. The monthly averaged values showed obvious periodicity, which was expressed in terms of sinusoidal function. The cycle was about one year, with the lowest value in July or August, and the highest value in November, December or January;Spatially, the NO2 column density in thecomparatively developed areas were higher than in the economic less-developed areas. From 2005 to 2012, for about 99.58% of the total area, the NO2 column density increased and from 2012 to 2017. for about 80.50% of the total area, the NO2 column density decreased. In general, from 2005 to 2017, in the eastern and western mountainous areas of CCUA, the NO2 column density showed an increasing trend, and there was a significantly positive spatial correlation in Chengdu and Chongqing.