Testing and improving OMI DOMINO tropospheric NO₂ using observations from the DANDELIONS and INTEX‐B validation campaigns

Abstract

[1] We present a sensitivity analysis of the tropospheric NO 2 retrieval from the Ozone Monitoring Instrument (OMI) using measurements from the Dutch Aerosol and Nitrogen Dioxide Experiments for Validation of OMI and SCIAMACHY (DANDELIONS) and Intercontinental Chemical Transport Experiment-B (INTEX-B) campaigns held in 2006. These unique campaigns covered a wide range of pollution conditions and provided detailed information on the vertical distribution of NO 2 . During the DANDELIONS campaign, tropospheric NO 2 profiles were measured with a lidar in a highly polluted region of the Netherlands. During the INTEX-B campaign, NO 2 profiles were measured using laser-induced fluorescence onboard an aircraft in a range of meteorological and polluted conditions over the Gulf of Mexico and the east Pacific. We present a comparison of measured profiles with a priori profiles used in the OMI tropospheric NO 2 retrieval algorithm. We examine how improvements in surface albedo estimates improve the OMI NO 2 retrieval. From these comparisons we find that the absolute average change in tropospheric columns retrieved with measured profiles and improved surface albedos is 23% with a standard deviation of 27% and no trend in the improved being larger or smaller than the original. We show that these changes occur in case studies related to pollution in the southeastern United States and pollution outflow in the Gulf of Mexico. We also examine the effects of using improved Mexico City terrain heights on the OMI NO 2 product.

Evaluation of OMI operational standard NO<sub>2</sub> column retrievals using in situ and surface-based NO<sub>2</sub> observations

“…Compared to the operational retrievals, the new retrievals are systematically lower by 16-19 % in rural locations and higher by 15-21 % in urban locations. These results are consistent with the previous study by Hains et al (2010), who evaluated the impact of a priori profiles in the Dutch NO 2 (DOMINO) retrievals using observations from the Dutch Aerosol and Nitrogen Dioxide Experiments for vaLIdation of OMI and SCIAMACHY (DAN-DELIONS) and Intercontinental Chemical Transport Experiment Phase B (INTEX-B) campaigns. Our use of measured profiles improved the correlation between OMI and aircraft measurements (r = 0.5, N = 59).…”

“…Tropospheric NO 2 column retrievals from satellites have been evaluated with in situ NO 2 profile measurements from aircraft (Heland et al, 2002;Martin et al, 2006;Boersma et al, 2008a;Bucsela et al, 2008Bucsela et al, , 2013Celarier et al, 2008;Hains et al, 2010), NO 2 column measurements from groundbased and airborne instruments Celarier et al, 2008;Brinksma et al, 2008;Kramer et al, 2008;Irie et al, 2008Irie et al, , 2012Wenig et al, 2008;Oetjen et al, 2013), in situ surface measurements (Schaub et al, 2006;Blond et al, 2007;Boersma et al, 2009;Lamsal et al, 2008Lamsal et al, , 2010, and a bottom-up NO x emission inventory (Lamsal et al, 2010). Aircraft offer precise in situ measurements within vertical spirals covering a spatial domain over a satellite field of view, but these are generally campaign-based experiments spanning only a few days to weeks and are limited by the need to extrapolate below the lowest measurement altitude (e.g.…”

Comparison of OMI NO<sub>2</sub> tropospheric columns with an ensemble of global and European regional air quality models

“…The tropospheric NO 2 DOMINO product has been validated against surface, in-situ and aircraft observations, such as during the INTEX-B and DANDELIONS campaigns (Boersma et al, 2008;Brinksma et al, 2008;Hains et al, 2010) and observations in Israel, (Boersma et al, 2009b). In general, the assumption of a well mixed boundary layer at OMI overpass (early afternoon) leads to a satisfactory comparison with surface NO 2 observations (Boersma et al, 2009b).…”

Intercomparison of slant column measurements of NO<sub>2</sub> and O<sub>4</sub> by MAX-DOAS and zenith-sky UV and visible spectrometers

“…2). This location was chosen because of its unobstructed views close to horizontal at many azimuth angles, its large variability in tropospheric NO 2 , the absence of local pollution sources, good local support because of its closeness to KNMI headquarters in De Bilt near Utrecht, and its tower of height over 200 m. The same site has been used for two previous MAX-DOAS campaigns focusing on validation of satellite observations (Brinksma et al, 2008;Hains et al, 2010). The Cabauw site has a large suite of meteorological instruments deployed continuously, specialising in the boundary layer.…”