Ozone pollution: What can we see from space? A case study

Abstract

Due to its impact on environment, tropospheric ozone received particular attention since several decades. Ground-based networks associated with regional chemical transport models are used to monitor and forecast surface ozone concentrations, but coverage, representativeness, and accuracy issues remain important. Recent satellite observations have demonstrated the capacity to probe tropospheric ozone, but there has been no explicit attempt to quantify their ability to measure ozone pollution near ground. We propose here to assess the ability of ozone sounders to detect a photochemical ozone pollution event that is supposed to be a favorable situation for satellite detection. We have chosen ozone pollution event over Europe associated with a warm conveyor belt that efficiently transports photochemically produced ozone upward. Ozone satellite products from Global Ozone Monitoring Experiment-2, Infrared Atmospheric Sounding Interferometer (IASI), and Ozone Monitoring Instrument are analyzed here for their capacity to capture such an event. Also, in situ observations and regional chemical-transport models show increasing ozone concentrations in the continental and Mediterranean boundary layer and further transport to central Europe and Scandinavia associated with upward transport. Satellite observations do not detect high ozone concentrations within the boundary layer due the weak sensitivity near the surface. Nevertheless, we have shown that the IR sounder IASI was able to detect, qualitatively and quantitatively, the ozone plume transported upward by the warm conveyor belt, suggesting that a quantification of upward transport of ozone pollution could be possible using current satellite observations. This should encourage us to further explore approaches more sensitive to surface ozone (such as the multispectral approach) and to prepare the next generation of still more sensitive spaceborne instruments.

The Ozone Monitoring Instrument: overview of 14 years in space

“…For PROFOZ, early versions were partially evaluated against ozonesonde, aircraft, MLS, surface measurements, model simulations, and tropospheric ozone derivations from other methods (Pittman et al, 2009;Liu et al, 2010bLiu et al, , 2013aZhang et al, 2010;Walker et al, 2010;Tarasick et al, 2010;Sellitto et al, 2011;Bak et al, 2013aBak et al, , b, 2015Foret et al, 2014;Ziemke et al, 2014). The analyses generally showed good agreement with other correlative data but revealed limited sensitivity to ozone in the lower troposphere and near the surface.…”

Satellite observation of lowermost tropospheric ozone by multispectral synergism of IASI thermal infrared and GOME-2 ultraviolet measurements over Europe

“…We analyse LT and LMT ozone observations for a typical ozone pollution outbreak over Europe during summer. It is a moderate ozone event, mainly occurring on 19 and 20 August 2009 (also analysed by Sellitto et al, 2013, andForet et al, 2013). Surface ozone concentrations occasionally reached 90 ppb (the ozone information threshold; e.g.…”

Potential of multispectral synergism for observing ozone pollution by combining IASI-NG and UVNS measurements from the EPS-SG satellite

“…Liu et al, 2010) and TIR sensors are particularly sensitive to tropospheric ozone, down to the lower troposphere (below 6 km altitude; Eremenko et al, 2008). However, it has been shown that when using space-borne observations from one spectral domain (either TIR or UV), only ozone down to 3-4 km altitude at the lowest may be observed with adequate vertical sensitivity (Foret et al, 2014). Recent studies combine the information on ozone distribution from radiance measurements of different spectral domains to enhance sensitivity in the LMT.…”