Remote sensing of Asian pollution from space: tracking the long range transport from China using ACE measurements.
Solène Turquety(1), Cathy Clerbaux(2), Pierre-François Coheur(3), Juliette Hadji-Lazaro(4), Ariane Razavi(3), Daniel Hurtmans(3), Curtis P. Rinsland(5), Chris Boone(6) and Peter Bernath(7)
(1) Service d'Aéronomie, IPSL, 4 Place Jussieu, 75252 Paris Cedex 05 , France
(2) Service d'Aéronomie, IPSL, 4, place Jussieu, 75252 Paris Cedex 05, France
(3) Spectroscopie de l’Atmosphère, Université Libre de Bruxelles, B-1050 Brussels, Belgium
(4) Service d'Aéronomie, IPSL, 4 Place Jussieu, 75252 Paris Cedex 05, France
(5) NASA Langley Research Center, Mail Stop 401A, Hampton, VA 23681-3142, United States
(6) Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
(7) Department of Chemistry , University of Waterloo , Waterloo, Ontario N2L 3G1, Canada
With more than half of the world’s population in its urban areas, Asia represents one of the most important pollution source regions. The cumulative effects of population growth, industrialization and increasing transportation could result in a significant enhancement of the emissions over this region. Furthermore, recent studies have shown that long range transport of pollution from Asia has significant influence on the chemical composition of the troposphere over the Pacific and downwind continents. The impact of this region on air quality, the global oxidizing capacity of the troposphere and climate therefore need to be analyzed and monitored on a local, regional and global scale.
In this study, we explore the information provided by the available satellite observations on the transport and production of pollutants in the troposphere above Asia and downwind. We use the observations collected in 2004 and 2005 by the Atmospheric Chemistry Experiment (ACE) on the Canadian Scisat satellite. The ACE Fourier transform infrared spectrometer operates in solar occultation and allows the measurement of a series of trace gases with high vertical resolution (~3km) from the middle troposphere to the thermosphere. Self-consistent measurements of ozone and its main precursors CO, VOCs (C2H6, HCN, CH3Cl, CH4) and NOx (NO, NO2), as well as HNO3 and possibly PAN, allow the analysis of the transport and photochemistry within Asian pollution plumes during long range transport.
However, the ACE measurement technique implies a limited coverage and does not allow for measurements below ~8km. Information from ACE are complemented with observation from the other satellite missions operating during the same time period: O3 from the TES/Aura instrument, CO measurements from the MOPITT/Terra and the TES/Aura instruments and NO2 from SCIAMACHY/Envisat. Their nadir viewing geometry allows a better spatial and temporal coverage and a good sensitivity to the free troposphere, but also implies a much lower vertical resolution. We examine the consistency and complementarities of the available observations.
Keywords: ESA European
Space Agency - Agence spatiale europeenne,
observation de la terre, earth observation,
satellite remote sensing,
teledetection, geophysique, altimetrie, radar,
chimique atmospherique, geophysics, altimetry, radar,