基于Pandora 观测的OMI 全球臭氧产品精度验证

臭氧是大气中一种重要的微量气体, 是影响对流层与平流层大气运动的重要成分之一, 臭氧的高精度探测 对于环境和气候具有重要的意义。OMI 传感器是目前具备探测全球臭氧含量的主要遥感传感器之一。利用地基 Pandora 观测网全球范围内44 个臭氧观测站点数据对OMI 卫星数据产品进行了精度验证。结果表明: OMI 臭氧产品 与Pandora 地基测量结果之间具有很好的线性相关性, 相关系数达到0.948, 但精度结果存在区域差异。在南半球地区, 相关系数为0.915; 在北半球低纬度地区, 其相关系数为0.932, 中纬度地区相关系数为0.948, 而在高纬度地区, 相关系 数达到了0.957。此外, 验证精度还与臭氧柱总量存在相关性, 在臭氧柱总量低于220 Du (对应臭氧空洞条件) 时, OMI 卫星产品存在高估现象, 高估约13%; 而在臭氧柱总量高于400 Du 时, OMI 的臭氧产品低于Pandora 地基测量结果, 且 随着臭氧柱总量增加, 低估情况也越严重, 在臭氧柱总量达到500 Du 时, OMI 臭氧产品低估约4%。

Accuracy verification of OMI global ozone products based on Pandora observations

As an important trace gas in the atmosphere, ozone is one of the important components that affect the movement of the atmosphere in the troposphere and stratosphere. The high-precision detection of ozone is of great significance to the environment and climate, and OMI sensor is currently one of the main remote sensing sensors capable of detecting global ozone levels. In this paper, the accuracy of OMI satellite data products is verified by using the data of 44 ozone observation stations around the world of the ground-based Pandora observation network. The results show that there is a good linear correlation between OMI ozone products and Pandora ground measurement results, with the correlation coefficient reaching 0.946. However, there are regional differences in the accuracy results. In the southern hemisphere, the correlation coefficient is 0.894. While in the northern hemisphere low latitudes, the correlation coefficient is 0.931, in the middle latitudes, the correlation coefficient is 0.951, and in the high latitudes, the correlation coefficient reaches 0.957. In addition, the verification accuracy is also related to the total ozone column. When the total ozone column is less than 220 Du (corresponding to the ozone hole condition), OMI satellite product is overestimated by about 13%. Above 400 Du, OMI′s ozone product is lower than Pandora′s ground-based measurement. And as the total ozone column increases, the underestimation becomes more serious. When the total ozone column reaches 500 Du, OMI′s ozone product is underestimated by about 4%.