Satellite derived trends in NO2 over the major global hotspot regions during the past decade and their inter-comparison

We assessed satellite derived tropospheric NO₂ distribution on a global scale and identified the major NO₂ hotspot regions. Combined GOME and SCIAMACHY measurements for the period 1996-2006 have been used to compute the trends over these regions. Our analysis shows that tropospheric NO₂ column amounts have increased over the newly and rapidly developing regions like China (11 ± 2.6%/year), south Asia (1.76 ± 1.1%/year), Middle East (2.3 ± 1%/year) and South Africa (2.4 ± 2.2%/year). Tropospheric NO₂ column amounts show some decrease over the eastern US (−2 ± 1.5%/year) and Europe (0.9 ± 2.1%/year). We found that although tropospheric NO₂ column amounts decreased over the major developed regions in the past decade, the present tropospheric NO₂ column amounts over these regions are still significantly higher than those observed over newly and rapidly developing regions (except China). Tropospheric NO₂ column amounts show some decrease over South America and Central Africa, which are major biomass burning regions in the Southern Hemisphere.     

利用SCIAMACHY遥感资料研究我国NO2柱浓度及其时空分布

利用SCIAMACHYENVISAT 2003—2009年月均观测数据,结合1∶4 000 000行政区划图,得到了近7 a来我国城市级别NO₂柱浓度的时空分布和变化趋势,并采用Seasonal Mann-Kendall非参数检验方法对各城市的变化趋势进行了显著性分析. 结果表明:我国NO₂分布东高西低,NO₂柱浓度高值区主要分布在京津冀及环渤海区域、长江三角洲北部及广东省等地区. 近7 a来我国北部和中部地区的NO₂增长趋势显著,NO₂柱浓度平均值最高和增速最快的前20个城市主要分布在江苏、山东和安徽等省的二级城市郊县和小城市. 与统计年鉴工业废气排放数据的比较表明,工业废气排放与NO₂柱浓度及其时空分布具有较好的一致性. 这种新的NO₂污染格局应该引起重视并采取有针对性的污染监管措施.      

亚洲地区OMI和SCIAMACHY臭氧柱总量观测结果比较

利用臭氧观测仪(OMI)和扫描成像大气吸收光谱仪(SCIAMACHY)传感器反演的臭氧总量数据,结合从世界臭氧与紫外线辐射数据中心(WODUC)获取的地面观测臭氧总量数据进行验证,对比2种不同卫星遥感反演的臭氧总量产品优缺点,并分析亚洲地区臭氧总量的时空特征.结果表明,OMI反演的结果比SCIAMACHY的结果更好,而且具有更高的时间和空间分辨率.臭氧总量存在明显的季节变化,在低纬度地区最大值出现在4或5月,最小值在11或12月,而在高纬度地区则分别出现在2月或3月和8月或9月.臭氧总量纬度地带性分布明显,并随着纬度增加而逐渐上升,在10°N~30°N之间,臭氧总量增长平缓,在30°N~50°N之间,臭氧总量快速增大.在青藏高原地区出现臭氧低值区,并在青藏高原东面的横断山脉向低纬度延伸,隔断了臭氧总量的纬度地带性分布.臭氧总量变化在不同纬度呈现不同的模式,距平值随纬度的增大波动随之增大.纬度最低的站点(216)臭氧总量距平值变化最小,最大只有30 DU;而纬度最高的站点(326)臭氧总量距平值变化可达180 DU以上.