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Validation of OMI tropospheric NO2 column data using MAX-DOAS measurements deep inside the North China Plain in June 2006 1Frontier Research Center for Global Change, Japan Agency for Marine-Earth Science and Technology, 3173-25 Showa-machi, Kanazawa-ku, Yokohama, Kanagawa 236-0001, Japan 2National Inst. for Environmental Studies, 16-2, Onogawa, Tsukuba, Ibaraki 305-8506, Japan 3LAPC/NZC, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China 4Atmospheric Chemistry and Dynamics branch, NASA Goddard Space Flight Center, Greenbelt, MD 20771-0000, USA 5SRI International, Menlo Park, CA 94107, USA Abstract. A challenge for the quantitative analysis of tropospheric nitrogen dioxide (NO2) column data from satellite observations is posed mainly by the lack of satellite-independent observations for validation. We performed such observations of the tropospheric NO2 column using the ground-based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) technique in the North China Plain (NCP) from 29 May to 29 June 2006. Comparisons between tropospheric NO2 columns measured by MAX-DOAS and the Ozone Monitoring Instrument (OMI) onboard the Aura satellite indicate that OMI data (the standard product, version 3) over NCP may have a positive bias of 1.6×1015 molecules cm−2 (20%), where the estimated random error in the OMI data is 0.6×1015 molecules cm−2 or approximately 8%. Combining these results with literature validation results for the US, Europe, and Pacific Ocean suggests that a bias of +20%/–30% is a reasonable estimate, accounting for different regions. Considering the uncertainty estimated here will pave the way for quantitative studies using OMI NO2 data, especially over NCP. Citation: Irie, H., Kanaya, Y., Akimoto, H., Tanimoto, H., Wang, Z., Gleason, J. F., and Bucsela, E. J.: Validation of OMI tropospheric NO2 column data using MAX-DOAS measurements deep inside the North China Plain in June 2006, Atmos. Chem. Phys. Discuss., 8, 8243-8271, doi:10.5194/acpd-8-8243-2008, 2008. |
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