Validation of Ozone Monitoring Instrument nitrogen dioxide columns

Abstract

[1] We review the standard nitrogen dioxide (NO 2 ) data product (Version 1.0.), which is based on measurements made in the spectral region 415-465 nm by the Ozone Monitoring Instrument (OMI) on the NASA Earth Observing System-Aura satellite. A number of ground-and aircraft-based measurements have been used to validate the data product's three principal quantities: stratospheric, tropospheric, and total NO 2 column densities under nearly or completely cloud-free conditions. The validation of OMI NO 2 is complicated by a number of factors, the greatest of which is that the OMI observations effectively average the NO 2 over its field of view (minimum 340 km 2 ), while a ground-based instrument samples at a single point. The tropospheric NO 2 field is often very inhomogeneous, varying significantly over tens to hundreds of meters, and ranges from <10 15 cm À2 over remote, rural areas to >10 16 cm À2 over urban and industrial areas. Because of OMI's areal averaging, when validation measurements are made near NO 2 sources the OMI measurements are expected to underestimate the ground-based, and this is indeed seen. Further, we use several different instruments, both new and mature, which might give inconsistent NO 2 amounts; the correlations between nearby instruments is 0.8-0.9. Finally, many of the validation data sets are quite small and span a very short length of time; this limits the statistical conclusions that can be drawn from them. Despite these factors, good agreement is generally seen between the OMI and ground-based measurements, with OMI stratospheric NO 2 underestimated by about 14% and total and tropospheric columns underestimated by 15-30%. Typical correlations between OMI NO 2 and ground-based measurements are generally >0.6.

Ground‐level nitrogen dioxide concentrations inferred from the satellite‐borne Ozone Monitoring Instrument

“…Comparison of the OMI-derived surface NO 2 with the PSS-NO 2 yields similar quantity. The bias reported here is consistent with the underestimate in OMI tropospheric NO 2 columns by 15 -30% versus independent column measurements as inferred by Celarier et al [2008], Bucsela et al [2008], and Wenig et al [2008]. The preferential placement of surface measurement sites near sources [Demerjian, 2000] also may contribute to the bias.…”

Evaluation of OMI operational standard NO&lt;sub&gt;2&lt;/sub&gt; column retrievals using in situ and surface-based NO&lt;sub&gt;2&lt;/sub&gt; observations

“…The OMNO2 retrievals used here, version 2.1 (Bucsela et al, 2013), represent a significant advance over previous version 1.0 Celarier et al, 2008). The main changes include the use of monthly, rather than annual, mean a priori NO 2 profiles, and improvements in the estimates of stratospheric NO 2 columns, correction of calibration artifacts (de-striping), and the calculation of scattering weights.…”

“…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.…”

Steps towards a mechanistic model of global soil nitric oxide emissions: implementation and space based-constraints

“…We use three independent retrievals of tropospheric NO 2 column data from OMI observations described briefly below: the Standard Product (SP) Level 2, Version 1.0.5, Collection 3 available from the NASA Goddard Earth Sciences Data and Information Services Center DISC (http: //daac.gsfc.nasa.gov/Aura/OMI/omno2.shtml) described in Bucsela et al (2006) and Celarier et al (2008), the GEOSChem DOMINO Product (DP GC) described in Lamsal et al (2010), and the Berkeley High Resolution Retrieval (BEHR) described in Russell et al (2011). The three products begin with the same NO 2 slant column densities.…”

“…NO 2 profiles are from a 2 • × 2.5 • gridded dataset of annual mean profiles from the GEOS-Chem model. A cross track bias correction is performed as described by Celarier et al (2008).…”