2005～2013年中国地区对流层二氧化氮分布及变化趋势

利用OMI探测器资料反演的对流层NO2柱浓度,结合REAS东亚地区NOx排放清单,ECMWF地面10m风场数据和中国统计年鉴中相关统计数据,研究了2005~2013年中国地区对流层NO2柱浓度的空间分布和长期变化趋势,NO2柱浓度的季节差异与排放源和地面风场的关系,以及国家政策实施情况与NO2柱浓度的关系.结果表明:中国地区NO2对流层柱浓度的高值区主要分布在华北地区、长江三角洲、珠江三角洲以及四川盆地等人口密集、人类活动频繁的大型城市和地区.NO2对流层柱浓度的变化存在东西部差异,值得注意的是东部在2011年之前基本表现为增加,但在2011年以后表现为下降,且与2011年相比年平均浓度下降了7.1%.工业氮氧化物排放总量的下降是2011年后NO2浓度下降的一个重要原因.西部浓度低于东部,但近9a浓度基本表现为增长.对流层柱浓度存在明显的季节差异,东部地区及大型城市基本表现为冬季高、夏季低.NOx人为排放源的季节差异是NO2浓度季节差异的重要因素之一,同时气象条件的作用不可忽视.

Distribution and long-term variation of tropospheric NO2 over China during 2005 to 2013

With the combination of NOx emission index of regional Emission inventory in Asia (REAS), the wind field at 10 meters height above surface which based on European Centre for Medium-Range Weather Forecasts (ECMWF) Real- Analysis data, and the relavant statistical data based on the China Statistical Yearbooks Database, the monthly tropospheric NO2 data over China acquired from the Ozone Monitoring Instrument (OMI) was analyzed with respect to spatial distribution and long-term trends between 2005 and 2013. The results showed that the high value areas of tropospheric NO2 columns over China were located on North China, the Yangtze River Delta, the Pearl River Delta and the Sichuan Basin. The trends of tropospheric NO2 columns were distinguished between east and west China. It was increased during 2005 to 2011 in east China, but decreased by 7.1% from 2011 to 2013. In west China, the tropospheric NO2 columns were increased continuously from 2005 to 2013. High value regions of NO2 tropospheric columns were decreased after 2011, which was strongly related to the cut of the NOx discharge of industry. The tropospheric NO2 columns reached their maximum in winter and minimum in summer. The anthropogenic emission of NOx was one of the important factors which influenced the seasonal mean tropospheric NO2 columns. In the mean time, seasonal means of 10-m winds also played an important role of influencing the seasonal distribution of tropospheric NO2 columns, which indicated that the impact of meteorological conditions should not be ignored.