Quantifying Smog Ozone Pollution and Its Formation from Space: DISCOVER-AQ Measurements Connect the Retrievable to the Relevant
Abstract
We may have considerable optimism that concentrations of pollutants retrievable from space are quite relevant in mapping near-surface O3 smog pollution. A general relationship obtains between O3 in near-surface layers - important for air pollution exposure assessment - and ozone in a deeper region of the troposphere - the thinnest layer to be retrieved potentially by remote sensing. This relationship has been observed where plentiful measurements of North American ozonesonde network. [Chatfield ..., AE, 2011]. Does it hold for complex urbanized and industrial regions? Does it hold for O3 precursors and for the O3 chemical production rate P(O3)? The answers determine the usefulness of proposed missions like NASA's GEO-CAPE geostationary observations. The DISCOVER-AQ airborne study repeatedly made spirals over various urban, industrial, transportation, and rural sites in detail around the Baltimore-Washington area in July, 2011. We compare mixing ratios appropriately averaged over a 0.2-3 km altitude and those measured at the bottom of the spirals, 0.2-0.5 km. The "retrievable" layer 0.2-3 km was set by GEO-CAPE remote-sensing sensitivity analyses for ozone [Natraj ..., AE submitted, 2011]. Correlations were quite good, ~0.9. Detailed comparison of various sites reveals more complexity. Comparisons for NO2 and HCHO m.r. and especially log(m.r.) have similar correlation but reflect a steeper m.r. decrease with altitude. These species allows us to estimate P(O3) and its controls with useful accuracy [Chatfield ..., AE, 2010]. Comparison all layer means to O3 monitors at the surface sites is more complex, since near-surface monitors suffer very local removal processes.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2011
- Bibcode:
- 2011AGUFM.A13E0367C
- Keywords:
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- 0345 ATMOSPHERIC COMPOSITION AND STRUCTURE / Pollution: urban and regional;
- 0365 ATMOSPHERIC COMPOSITION AND STRUCTURE / Troposphere: composition and chemistry;
- 0394 ATMOSPHERIC COMPOSITION AND STRUCTURE / Instruments and techniques