Zhang Yujing, Li Jie, Li Jianjun, Pan Xiaole, Wang Wei, Zhu Lili, Wang Zixi, Chen Xueshun, Yang Wenyi, Wang Zifa
The State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
The State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
J Environ Sci (China). 2022 Apr;114:514-525. doi: 10.1016/j.jes.2022.01.045. Epub 2022 Feb 7.
Spatiotemporal variations of ozone (O) taken from the Copernicus Atmosphere Monitoring Service (CAMS) and the second Modern-Era Retrospective Analysis for Research and Applications (MERRA-2) were intercompared and evaluated with ground and ozone-sonde observations over China in 2018 and 2019. Intercomparison of the surface ozone from CAMS and MERRA-2 reanalysis showed significant negative bias (CAMS minus MERRA-2, same below) at Tibetan Plateau of up to 80 µg/m, and the average R was about 0.6 across China. Evaluated with the ground observations from China National Environmental Monitoring Center (CNEMC), we found that CAMS and MERRA-2 reanalysis were capable of capturing the key patterns of monthly and diurnal variations of surface ozone over China except for the western region, and MERRA-2 overestimated the observations compared to CAMS. Vertically, the CAMS profiles overestimated the ozone-sonde from the World Ozone and Ultraviolet Radiation Data Center (WOUDC) above 200 hPa with the magnitude reaching up to 150 µg/m, while little bias was found between the reanalysis and observations below 200 hPa. Intercomparison drawn from the vertical distribution between CAMS and MERRA-2 reanalysis showed that the negative bias appeared throughout the troposphere over China, while the positive bias emerged in the upper troposphere and lower stratosphere (UTLS) with high order of magnitude exceeding 100 µg/m, indicating large uncertainties at higher altitudes. In summary, we concluded that CAMS reanalysis showed better agreement with the observations in contrast to MERRA-2, and the large discrepancy especially at higher altitudes between these two reanalysis datasets could not be ignored.
对取自哥白尼大气监测服务（CAMS）和第二代现代气候研究与应用回顾性分析（MERRA - 2）的臭氧（O₃）时空变化进行了相互比较，并与2018年和2019年中国地面及臭氧探空观测数据进行了评估。CAMS和MERRA - 2再分析资料的地表臭氧相互比较显示，青藏高原存在高达80μg/m³的显著负偏差（CAMS减去MERRA - 2，下同），全国平均相关系数约为0.6。用中国国家环境监测中心（CNEMC）的地面观测数据评估发现，CAMS和MERRA - 2再分析能够捕捉到中国除西部地区外地表臭氧月变化和日变化的关键模式，且与CAMS相比，MERRA - 2高估了观测值。在垂直方向上，CAMS廓线在200hPa以上高估了世界臭氧和紫外线辐射数据中心（WOUDC）的臭氧探空观测值，偏差幅度高达150μg/m³，而在200hPa以下再分析与观测值之间偏差较小。CAMS和MERRA - 2再分析垂直分布的相互比较表明，中国对流层整体存在负偏差，而在对流层上部和平流层下部（UTLS）出现正偏差，偏差量级超过100μg/m³，表明较高海拔处存在较大不确定性。总之，我们得出结论，与MERRA - 2相比，CAMS再分析与观测值的一致性更好，这两个再分析数据集之间尤其是在较高海拔处的巨大差异不容忽视。
