David Cabrera-Perez1, Domenico Taraborrelli1,a, Rolf Sander1, and Andrea Pozzer1
1Atmospheric Chemistry Department, Max-Planck Institute of Chemistry, Hahn-Meitner-Weg 1, 55128 Mainz,
Germany
anow at: Institute of Energy and Climate Research (IEK-8), Forschungszentrum Jülich GmbH, Jülich, Germany
Received: 09 Dec 2015 – Discussion started: 23 Feb 2016
Revised: 18 May 2016 – Accepted: 24 May 2016 – Published: 07 Jun 2016
Abstract. The global atmospheric budget and distribution of monocyclic aromatic compounds is estimated, using an atmospheric chemistry general circulation model. Simulation results are evaluated with an ensemble of surface and aircraft observations with the goal of understanding emission, production and removal of these compounds.
Anthropogenic emissions provided by the RCP database represent the largest source of aromatics in the model (≃ 23 TgC year−1) and biomass burning from the GFAS inventory the second largest (≃ 5 TgC year−1). The simulated chemical production of aromatics accounts for ≃ 5 TgC year−1. The atmospheric burden of aromatics sums up to 0.3 TgC. The main removal process of aromatics is photochemical decomposition (≃ 27 TgC year−1), while wet and dry deposition are responsible for a removal of ≃ 4 TgC year−1.
Simulated mixing ratios at the surface and elsewhere in the troposphere show good spatial and temporal agreement with the observations for benzene, although the model generally underestimates mixing ratios. Toluene is generally well reproduced by the model at the surface, but mixing ratios in the free troposphere are underestimated. Finally, larger discrepancies are found for xylenes: surface mixing ratios are not only overestimated but also a low temporal correlation is found with respect to in situ observations.
Citation:
Cabrera-Perez, D., Taraborrelli, D., Sander, R., and Pozzer, A.: Global atmospheric budget of simple monocyclic aromatic compounds, Atmos. Chem. Phys., 16, 6931-6947, https://doi.org/10.5194/acp-16-6931-2016, 2016.