Estimating European volatile organic compound emissions using satellite observations of formaldehyde from the Ozone Monitoring Instrument 1CETEMPS-Dipartimento di Fisica, Università degli Studi dell'Aquila, L'Aquila, Italy
03 Dec 2010
2School of GeoSciences, University of Edinburgh, Edinburgh, UK
3Atomic and Molecular Physics Division, Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA
Received: 14 Jul 2010 – Published in Atmos. Chem. Phys. Discuss.: 20 Aug 2010 Abstract. Emission of non-methane Volatile Organic Compounds (VOCs) to the atmosphere
stems from biogenic and human activities, and their estimation is difficult
because of the many and not fully understood processes involved. In order to
narrow down the uncertainty related to VOC emissions, which negatively
reflects on our ability to simulate the atmospheric composition, we exploit
satellite observations of formaldehyde (HCHO), an ubiquitous oxidation
product of most VOCs, focusing on Europe. HCHO column observations from the
Ozone Monitoring Instrument (OMI) reveal a marked seasonal cycle with a
summer maximum and winter minimum. In summer, the oxidation of methane and
other long-lived VOCs supply a slowly varying background HCHO column, while
HCHO variability is dominated by most reactive VOC, primarily biogenic
isoprene followed in importance by biogenic terpenes and anthropogenic VOCs.
The chemistry-transport model CHIMERE qualitatively reproduces the temporal
and spatial features of the observed HCHO column, but display regional
biases which are attributed mainly to incorrect biogenic VOC emissions,
calculated with the Model of Emissions of Gases and Aerosol from Nature
(MEGAN) algorithm. These "bottom-up" or a-priori emissions are corrected
Bayesian inversion of the OMI HCHO observations. Resulting "top-down" or
a-posteriori isoprene emissions are lower than "bottom-up" by 40% over
and by 20% over Southern Germany, and higher by 20% over Iberian
Peninsula, Greece and Italy.
We conclude that OMI
satellite observations of HCHO can provide a quantitative "top-down"
constraint on the European "bottom-up" VOC inventories.
Revised: 28 Nov 2010 – Accepted: 29 Nov 2010 – Published: 03 Dec 2010
Citation: Curci, G., Palmer, P. I., Kurosu, T. P., Chance, K., and Visconti, G.: Estimating European volatile organic compound emissions using satellite observations of formaldehyde from the Ozone Monitoring Instrument, Atmos. Chem. Phys., 10, 11501-11517, doi:10.5194/acp-10-11501-2010, 2010.