基于OMI数据的西南地区对流层NO2浓度时空变化特征分析

Spatial and Temporal Variation of Tropospheric NO2 Concentration in Southwest China Based on OMI Satellite Data

利用OMI数据反演得到的多时相NO2浓度产話(空间分辨率为0.125°X0.125°),分析了2005-2017年西南地区四省市(云南省、贵州省、四川省及重庆市)对流层NO2柱浓度的时空分布特征,并对其影响因素进行了简单分析。结果表明:(1)2005-2017年间,西南地区NO2柱浓度年均值较小,13年的年均值为1.8015 x 10^15molec/cm^2.年变化整体表现为先增大后减小趋势;季节变化表现为:冬季〉秋季〉春季〉夏季,而月变化呈内凹型分布;(2)空间分布上呈东部高、西部低的特点,并且跨度较大,四川省东部和重庆市西部地区的NO2柱浓度年均值大于10.0 x 10^15molec/cm^2,而四川省西部和云南省中西部地区的NO2柱浓度低于1.0 X 10^15molec/cm^2;(3)云南省的NO2柱浓度最低,重庆市的NO2柱浓度远远高于其他3个省;此外,云南省的年变化最为平缓,而重庆市的变化幅度最大;(4)研究区的地理位置及地形特征、气象要素、人口密集度及经济发展状况等因素都直接影响对流层NO2柱浓度的时空分布。

This paper analyzed the temporal and spatial distribution characteristics of tropospheric N02 column concentration in Southwest China(Yunnan,Guizhou,Sichuan and Chongqing)from 2005 to 2017 using multi-temporal N02 concentration products obtained by OMI data inversion,and then analyzed the influencing factors briefly.The results showed that:(1)In the year 2005~2017,the annual N02 column concentrations in Southwest China were small,the annual average of 13 years was 1.8015 X 10^15 molec/cm^2.The overall annual variation showed the trend of increase first and then decrease.Seasonal changes presented as:winter>autumn>spring>summer.The monthly variation showed an inner concave distribution.(2)The spatial distribution was characterized by high in the east and low in the west,and the span was comparatively large.The mean annual concentration of NO2 column was greater than 10.0 x 10^15 molec/cm^2 in eastern Sichuan Province and western Chongqing Province.The mean annual concentration of NO2 column was lower than 1.0 X 10^15 molec/cm^2 in western Sichuan Province and central western Yunnan Province.(3)Yunnan had the lowest concentration of N02 column,while Chongqing had the highest.In addition,the annual variation of Yunnan was most gradual,while that of Chongqing was maximum.(4)The geographical and topographical features,meteorological elements,population intensity and economic development of the study area directly affect the spatial and temporal distribution of tropospheric NO2 column concentration.