郑州市对流层NO2柱浓度时空变化及其影响因素

基于郑州市2005—2015年的OMI遥感反演资料以及地面相关监测数据,研究了郑州市对流层NO_2的时空分布特征,并利用灰色关联法对郑州市NO_2柱浓度变化的主要影响因素进行分析。与地面观测数据对比检验显示,对流层NO_2柱浓度年均值数据与近地面监测站NO_2浓度的实测年均值数据呈显著的正相关,相关系数分别为0.884 6和0.940 2,表明OMI数据资料可以较好地反映地面NO_2浓度的变化。郑州市的对流层NO_2柱浓度在2005—2013年间呈现波动变化且2013—2015年NO_2柱浓度显著减小的特征。季节变化上NO_2柱浓度主要表现为冬季秋季春季夏季的特点。郑州市对流层NO_2柱浓度的空间变化分布主要表现为由北部向南部逐渐递减的趋势,年际变化上高值区与低值区变化不够显著,中值区近年来不断扩大。灰色关联度分析结果显示,汽车保有量与对流层NO_2柱浓度的灰色关联度最低为0.571,而标准煤消耗量、工业用电量以及采暖供热量与对流层NO_2柱浓度的灰色关联度比较高,分别为0.956、0.828、0.862,即大气中工业过程及采暖期煤炭燃烧排放的NO_2占较大比例,汽车尾气排放所占的比例相对较小。

Spatial-Temporal Changes of Tropospheric NO2 Column Density and Its Impact Factors in Zhengzhou

Based on remote sensing data derived from OMI sensor and ground-based observation data in Zhengzhou during 2005-2015, spatial-temporal distribution characteristics of local tropospheric NO₂ was studyed, and then the main influencing factors of NO₂ concentration change were analyzed by gray relational method. Compared with the ground observation data, the OMI data showed significant positive correlation with the ground monitoring results and the correlation coefficient was 0.8846 and 0.9402 respectively. The OMI data can better reflect the change of ground concentration of NO₂. The tropospheric NO₂ column density was fluctuated change from 2005 to 2013 and then was significantly reduced in the last two years. Seasonal variation on the concentration of NO₂ column was mainly for the winter > autumn > spring > summer. Tropospheric NO₂ column density spatial distribution showed gradually decreasing trend from north to south in Zhengzhou. The interannual variability of high values and lowervalues areas were not obvious, the median area in recent years continued to expand. The results of grey correlation analysis showed that car ownership and tropospheric NO₂ column density of gray correlation degree a minimum of 0.571. The gray correlation degree of standard coal consumption, industrial electricity consumption as well as heating with tropospheric NO₂ column density was relatively high, which was 0.956, 0.828 and 0.862 respectively. The atmosphere NO₂ emissions from industrial process and coal combustion accounts for relatively a large proportion, while the proportion of vehicle emissions was relatively small.