2005~2016年中国大气边界层SO2的时空变化趋势

利用臭氧观测仪（OMI）卫星遥感反演的大气边界层（PBL）SO₂柱含量（PBL SO₂）数据分析了自2005年以来中国PBL SO₂柱含量数据的空间分布特征、变化趋势及其影响的原因.从长时间尺度上，PBL SO₂柱含量呈现明显的下降趋势.2005年中国区域年平均PBL SO₂柱含量为0.317DU，2016年为0.276DU，减少了0.041DU，大约为13.2%.SO₂柱含量呈现明显的周期变化特征.冬季浓度较高，夏季较低，最小值和最大值分别出现在7和12月，分别为0.246和0.404DU.小波分析显示SO₂的变化在10个月的尺度水平上存在明显的主振荡周期，在40个月的尺度水平上存在明显的次周期变化.中国区域SO₂污染严重的高值区主要出现在京津冀鲁环渤海地区、关中平原（山西省和陕西省）、河南省大部分地区、四川盆地、长江三角洲地区和珠江三角洲.最大的SO₂柱含量值可达1.1DU以上.京津冀鲁环渤海地区的高值区已经延伸到长江三角洲地区，有向南延伸和珠江三角洲连在一起的趋势.由于地形和天气特征的影响，四川盆地地区SO₂出现次高值区.在青藏高原和西北地区，SO₂浓度较低，呈现背景值特征，多年平均的SO₂约在0.05DU的水平.中国区域SO₂变化趋势在空间分布上存在明显的区域差异，变化的范围在-0.70~0.15DU之间.SO₂出现逐渐减少的地区主要是在高值区，如京津冀鲁环勃海地区、关中平原、四川盆地，长江中下游和珠江三角洲.减幅最大的是四川盆地和珠江三角洲，大约减少了61%.四川盆地2005~2016年约减少了0.55DU；珠江三角洲约减少了0.45DU.出现增长的地区主要是西部和北部地区，以及东南沿海除珠三角外的大部分区域，最大增长大约为0.15DU.

Trend of temporal and spatial variation of planetary boundary layer SO2 over China from 2005 to 2016

We analyzed the spatial distribution and variation trend of PBL SO₂ over China using the satellite retrieved data from the ozone monitoring instrument (OMI) sensor. In the long term scale, the SO₂ presented an obvious decline trend. The regional mean value has reduced 0.041DU (about 13.2%) from 2005 to 2016. The SO₂ showed an obvious periodic variation, the value was higher in winter and lower in summer. The smallest and largest value appeared in July and December with 0.246 and 0.404DU respectively. The wavelet analysis finding showed that the variation of SO₂ have primary period in 10months scale. In the spatial scale, there were 4 higher value regions over Circum-Bohai-Sea region, Sichuan Basin, Yangtze River Delta, and Pearl River Delta. The Largest value was up to 1.1DU over Bohai Rim Economic Zone. The higher value areas of the Circum-Bohai-Sea region in North China has been extended to the Yangtze River Delta region, with the southward extension to the Pearl River Delta. The SO₂ in the Sichuan Basin have higher values due to the influence of topography and weather characteristics. In the Tibetan Plateau and Northwest China, the SO₂ concentration was low, indicated the background value characteristics, the multi-yearly average SO₂ was about 0.05DU. There were obvious differences in the spatial distribution of variation trends of SO₂ over China. The range of variation was between -0.70 and 0.15DU. The gradual decreasing region of SO₂ appeared in high-value areas, such as Circum-Bohai-Sea region, Sichuan Basin, the Yangtze River and the Pearl River Delta. The largest reduction was about 61%, which reduced by about 0.55 and 0.45DU over Sichuan Basin and the Pearl River Delta from 2005 to 2016, respectively. The gradually increasing regions were mainly in the western and northern region, and the southeast coast excluding the Pearl River Delta. The maximum growth was about 0.15DU.