title: Substantial Underestimation of Post-Harvest Burning Emissions in the North China Plain Revealed by Multi-Species Space Observations.
abstract: The large-scale burning of crop residues in the North China Plain (NCP), one of the most densely populated world regions, was recently recognized to cause severe air pollution and harmful health effects. A reliable quantification of the magnitude of these fires is needed to assess regional air quality. Here, we use an eight-year record (2005-2012) of formaldehyde measurements from space to constrain the emissions of volatile organic compounds (VOCs) in this region. Using inverse modelling, we derive that satellite-based post-harvest burning fluxes are, on average, at least a factor of 2 higher than state-of-the-art bottom-up statistical estimates, although with significant interannual variability. Crop burning is calculated to cause important increases in surface ozone (+7%) and fine aerosol concentrations (+18%) in the North China Plain in June. The impact of crop fires is also found in satellite observations of other species, glyoxal, nitrogen dioxide and methanol, and we show that those measurements validate the magnitude of the top-down fluxes. Our study indicates that the top-down crop burning fluxes of VOCs in June exceed by almost a factor of 2 the combined emissions from other anthropogenic activities in this region, underscoring the need for targeted actions towards changes in agricultural management practices.
authors: Royal Belgian Institute for Space Aeronomy, Avenue Circulaire 3, 1180, Brussels, Belgium.
authors: T
authors: T
authors: Stavrakou
authors: Royal Belgian Institute for Space Aeronomy, Avenue Circulaire 3, 1180, Brussels, Belgium.
authors: J-F
authors: JF
authors: Müller
authors: Royal Belgian Institute for Space Aeronomy, Avenue Circulaire 3, 1180, Brussels, Belgium.
authors: M
authors: M
authors: Bauwens
authors: Royal Belgian Institute for Space Aeronomy, Avenue Circulaire 3, 1180, Brussels, Belgium.
authors: I
authors: I
authors: De Smedt
authors: Royal Belgian Institute for Space Aeronomy, Avenue Circulaire 3, 1180, Brussels, Belgium.
authors: C
authors: C
authors: Lerot
authors: Royal Belgian Institute for Space Aeronomy, Avenue Circulaire 3, 1180, Brussels, Belgium.
authors: M
authors: M
authors: Van Roozendael
authors: Spectroscopie de l'Atmosphère, Service de Chimie Quantique et Photophysique, Université Libre de Bruxelles (ULB), 1050, Belgium.
authors: P-F
authors: PF
authors: Coheur
authors: Spectroscopie de l'Atmosphère, Service de Chimie Quantique et Photophysique, Université Libre de Bruxelles (ULB), 1050, Belgium.|LATMOS/IPSL, UPMC Univ. Paris 06 Sorbonne Universités, UVSQ, CNRS, Paris, France.
authors: C
authors: C
authors: Clerbaux
authors: Royal Netherlands Meteorological Institute, De Bilt, The Netherlands.|Wageningen University, Meteorology and Air Quality department, Wageningen, The Netherlands.
authors: K F
authors: KF
authors: Boersma
authors: Royal Netherlands Meteorological Institute, De Bilt, The Netherlands.
authors: R
authors: R
authors: van der A
authors: Department of Environmental Science, Peking University, Beijing 100871, China.
authors: Y
authors: Y
authors: Song
mesh_terms: D000336:Aerosols; D000383:Agriculture; D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000032:analysis; D001272:Atmosphere; D002681:China; D018556:Crops, Agricultural; D004784:Environmental Monitoring; D005390:Fires; D005557:Formaldehyde / Q000032:analysis; D006037:Glyoxal / Q000032:analysis; D000432:Methanol / Q000032:analysis; D009585:Nitrogen Dioxide / Q000032:analysis; D010126:Ozone / Q000032:analysis; D052638:Particulate Matter / Q000032:analysis*
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D052638:Particulate Matter; D005557:Formaldehyde; D006037:Glyoxal; D010126:Ozone; D009585:Nitrogen Dioxide; D000432:Methanol