Validation of Ozone Monitoring Instrument NO2 measurements using ground based NO2 measurements at Zvenigorod, Russia

This article may be used for research, teaching and private study purposes. Any substantial or systematic reproduction, redistribution , reselling , loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material. We present the results of comparison between Ozone Monitoring Instrument (OMI) data of NO 2 measurements (Collection 3) onboard the NASA EOS-Aura satellite and correlative ground-based twilight measurements at Zvenigorod station in Russia in 2004–2008. Compared quantities are unpolluted column and tropospheric column amounts of NO 2 which are standard products of OMI measurements. The NO 2 columns observed by our ground-based instrument have been interpolated to the time of OMI measurements using a one-dimensional photochemical model. According to our comparison, the OMI unpolluted NO 2 columns underestimate ground-based measurements by (0.084 AE 0.025) Â 10 15 molecules/cm 2 , or (3.2 AE 0.9)%. The correlation coefficient between the OMI and ground-based unpolluted NO 2 columns is 0.92. The tropospheric NO 2 columns derived from OMI measurements are on average by (1.8 AE 0.5) Â 10 15 cm-2 , or approximately 40%, less than those derived from ground-based measurements. The correlation coefficient between these data is about 0.3. Reasons for this discrepancy are discussed.