近10年长江三角洲对流层NO_2柱浓度时空变化及影响因素

Spatio-temporal change and influencing factors of tropospheric NO_2 column density of Yangtze River Delta in the decade

利用臭氧监测仪(OMI)卫星遥感数据,分析了2005~2014 10年间长江三角洲对流层NO_2柱浓度时空变化格局,从地形、气象、经济、农业、生活、国家重大环保措施及规划等多个方面分析了NO_2变化的影响因素,结果表明:(1)长江三角洲对流层NO_2柱浓度十年年均增长率为1.04%.2011年最高,为1184.07×10^(13)mole/cm^2.2010年较2005年上升20.75%;2014年较2010年下降9.10%;(2)长江三角洲对流层NO_2柱浓度呈中间高、北部次之、南部低的趋势.长江三角洲中部的上海、苏州、无锡、常州、镇江和南京等城市为中心的条带状区域是四、五级高浓度中心,浙江大部份一直处于一、二级较低浓度水平;(3)长江三角洲夏季降水量大,与NO_2浓度负相关系数高达0.84,对NO_2具有湿沉降的作用.长江三角洲北风的主导风向及北平南高的地势特点决定了其中部高污染区对浙江中南部影响较小;(4)对流层NO_2浓度与第二产业产值相关系数高达0.83,与汽车保有量相关系数为0.74.对流层NO_2浓度与煤炭消费量及汽车保有量紧密相关,此外,农业秸秆焚烧也释放大量氮氧化物."十二五"期间实施的燃煤量控制和脱硝等一系列氮氧化物排放控制措施等使得2012~2014年NO_2浓度降低.

The characteristics of spatial and temporal distribution of tropospheric NO2 column density over Yangtze River Delta for 2005~2014 were analysed based on satellite derived NO2 column data from OMI. On this basis, influencing factors of NO2 changes were analysed from terrain, meteorology, economy, agriculture, life, national major environmental planning, and other aspects. Results demonstrate： a） Tropospheric NO2 column density increased at the annual rate of 1.04%, with the highest column density 1184.07×1013 mole/cm2 in 2011; it raised 20.7% compared with 2005 in 2010 and declined 9.1% compared with 2010 in 2014; b） The spatial distribution of tropospheric NO2 column density had significant change, high in the middle, low in northern and lower in southern of Yangtze River Delta. c） Precipitation had a highly negative correlation with NO2 concentrations for the reason of atmospheric wet deposition. The terrain of Yangtze River delta weakened the unfavorable impact of the high polluted area under the effect of the dominant north wind. d） Tropospheric NO2 concentration had a correlation coefficient of 0.83 with the second industry output value, and a correlation coefficient of 0.74 with car ownership. Tropospheric NO2 concentration was closely related to coal consumption and car ownership; in addition, the agricultural straw burning also released a large amount of nitrogen oxides. Series of NOx emission control measures such as controlling amount of coal and denitration applied during the＆quot;twelfth five-year＆quot; lowered the NO2 concentration in 2012~2014.