基于OMI数据的中国NO2时空分布与人类影响分析

近年来,空气质量不断恶化,严重威胁人类身体健康。二氧化氮(NO2)作为人类排放的重要污染物之一,实时监测其时空分布及含量,对空气质量研究及公众安全预警具有重要意义。本研究利用搭载在AURA卫星上的OM(IOzone Monitoring Instrument)传感器反演获取的2005年1月至2010年12月中国区的NO2数据,探究了NO2的时空分布特征及其人类影响。结果表明:中国NO2浓度上升趋势显著,6年来总NO2柱浓度(TotNO2)和对流层柱浓度(TropNO2)净增值分别为0.61×1015molec/cm2和0.63×1015molec/cm2,年均增长率为2.47%和5.69%;全国绝大部分地区NO2浓度呈增长趋势,但增长速率在空间上有所差异,表现为东部沿海地区大于西部欠发达地区。在全国尺度上,NO2呈现显著的时空分布差异特征:空间上,总体呈东高西低态势;时间上,东部地区的NO2浓度冬季明显高于夏季,西部地区则相反。最后,对比分析了TropNO2/TotNO2与人类足迹的相关性,结果显示二者间呈显著相关,且冬季最大,夏季最小。同时,分析发现各地地区生产总值和全国汽车保有量与对流层NO2间呈较强相关性。表明人类活动和经济发展是导致大气中NO2增多的主要原因。

Spatio-temporal Characteristics of NO2 in China and the Anthropogenic Influences Analysis Based on OMI Data

Recently, the air quality is deteriorating continuously, do serious harm to human health. As one of the major primary pollutants produced by human activities, real-time monitoring of the spatio-temporal characteris- tics of NO2 and its content can make a big difference to the air quality studies and public safety warning. This re- search studied the OMNO2e data between January 2005 and December 2010 from the Ozone Monitoring Instru- ment and the human society factors in China, explored the spatio-temporal characteristics of NO2 in China and the anthropogenic influences on it. The results showed that： the average NO2 column concentration in China has a significant upward trend from 2005 to 2010, the total column concentration in the atmosphere increased by 0.61 x 10~Smolec/cm2, with an average annual growth rate of 2.47%; while the tropospheric column concentration in- creased by 0.63 ~ 10＇Smolec/cm2, with an average annual growth rate of 5.69%. The NO2 column concentration in most areas of China increased rapidly, and the growth rate in eastern China was much greater than the less devel- oped regions in western China. The spatial distribution of NO： in China also shows a significant difference. In general, it presents the characteristic of higher in the east than that in the west. Besides, NO2 column concentra- tion in winter was significantly higher than that in summer in eastern China, but in western, the highest value ap- pears in summer. We also studied the relationship between every season＇ s spatial distribution of TropNOJTot- NO2 and the human footprint. The result showed a good consistency between them： the correlation coefficients between TropNOJTotNO2 and human footprint is maximum in winter, about 0.59; and its minimum value ap- pears in summer, about 0.48. And the number of samples is 56166~2, indicated that the influences from human activities were maximal in winter and minimum in summer. The correlation coefficients between car ownership and TropNO2, gross regional production and TropNO2 had also been calculated. We found that the coefficient be- tween car ownership and TropNO2 is 0.95, with a significance test at 95 percentile of confidence level, and the correlation between gross regional production and TropNO2 also very strong. The increasing of NO2 in China has remarkable relevance with human activities and social economic development.