Observation of slant column NO<sub>2</sub> using the super-zoom mode of AURA-OMI
We retrieve slant column NO<sub>2</sub> from the super-zoom mode of the Ozone Monitoring Instrument (OMI) to explore its utility for understanding NO<sub>x</sub> emissions and variability. Slant column NO<sub>2</sub> is operationally retrieved from OMI (Boersma et...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2011-09-01
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| Series: | Atmospheric Measurement Techniques |
| Online Access: | http://www.atmos-meas-tech.net/4/1929/2011/amt-4-1929-2011.pdf |
| Summary: | We retrieve slant column NO<sub>2</sub> from the super-zoom mode of the Ozone Monitoring Instrument (OMI) to explore its utility for understanding NO<sub>x</sub> emissions and variability. Slant column NO<sub>2</sub> is operationally retrieved from OMI (Boersma et al., 2007; Bucsela et al., 2006) with a nadir footprint of 13 × 24 km<sup>2</sup>, the result of averaging eight detector elements on board the instrument. For 85 orbits in late 2004, OMI reported observations from individual "super-zoom" detector elements (spaced at 13 × 3 km<sup>2</sup> at nadir). We assess the spatial response of these individual detector elements in-flight and determine an upper-bound on spatial resolution of 9 km, in good agreement with on-ground calibration (7 km FWHM). We determine the precision of the super-zoom mode to be 2.1 × 10<sup>15</sup> molecules cm<sup>−2</sup>, approximately a factor of √8 lower than an identical retrieval at operational scale as expected if random noise dominates the uncertainty. We retrieve slant column NO<sub>2</sub> over the Satpura power plant in India; Seoul, South Korea; Dubai, United Arab Emirates; and a set of large point sources on the Rihand Reservoir in India using differential optical absorption spectroscopy (DOAS). Over these sources, the super-zoom mode of OMI observes variation in slant column NO<sub>2</sub> of up to 30 × the instrumental precision within one operational footprint. |
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| ISSN: | 1867-1381 1867-8548 |