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Williams, J.; Custer, T.; Riede, H.; Sander, R.; Joeckel, P.; Hoor, P.; Pozzer, A.; Wong-zehnpfennig, S.; Beygi, Z. Hosaynali; Fischer, H.; Gros, V.; Colomb, A.; Bonsang, B.; Yassaa, N.; Peeken, I.; Atlas, E. L.; Waluda, C. M.; Van Aardenne, J. A.; Lelieveld, J.. |
Ship-borne measurements have been made in air over the remote South Atlantic and Southern Oceans in January-March 2007. This cruise encountered a large-scale natural phytoplankton bloom emitting reactive hydrocarbons (e. g. isoprene); and a high seas squid fishing fleet emitting NOx (NO and NO2). Using an atmospheric chemistry box model constrained by in-situ measurements, it is shown that enhanced ozone production ensues from such juxtaposed marine biogenic and anthropogenic emissions. The relative impact of shipping and phytoplankton emissions on ozone was examined on a global scale using the EMAC model. Ozone in the marine boundary layer was found to be over ten times more sensitive to NOx emissions from ships, than to marine isoprene in the region... |
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Ano: 2010 |
URL: https://archimer.ifremer.fr/doc/00231/34260/32628.pdf |
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Beygi, Z. Hosaynali; Fischer, H.; Harder, H. D.; Martinez, M.; Sander, R.; Williams, J.; Brookes, D. M.; Monks, P. S.; Lelieveld, J.. |
Ozone (O-3) is a photochemical oxidant, an air pollutant and a greenhouse gas. As the main precursor of the hydroxyl radical (OH) it strongly affects the oxidation power of the atmosphere. The remote marine boundary layer (MBL) is considered an important region in terms of chemical O-3 loss; however surface-based atmospheric observations are sparse and the photochemical processes are not well understood. To investigate the photochemistry under the clean background conditions of the Southern Atlantic Ocean, ship measurements of NO, NO2, O-3, J(NO2), J((OD)-D-1), HO2, OH, ROx and a range of meteorological parameters were carried out. The concentrations of NO and NO2 measured on board the French research vessel Marion-Dufresne (28 degrees S-57 degrees S, 46... |
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Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00092/20310/17959.pdf |
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Fischer, H.; Pozzer, A.; Schmitt, T.; Joeckel, P.; Klippel, T.; Taraborrelli, D.; Lelieveld, J.. |
In the OOMPH (Ocean Organics Modifying Particles in both Hemispheres) project a ship measurement cruise took place in the late austral summer from 01 to 23 March 2007. The French research vessel Marion Dufresne sailed from Punta Arenas, Chile (70.85A degrees W, 53.12A degrees S), to R,union island (55.36A degrees E, 21.06A degrees S) across the South Atlantic Ocean. In situ measurements of hydrogen peroxide, methylhydroperoxide and ozone were performed and are compared to simulations with the atmospheric chemistry global circulation model EMAC (ECHAM/MESSy Atmospheric Chemistry). The model generally reproduces the measured trace gas levels, but it underestimates hydrogen peroxide mixing ratios at high wind speeds, indicating too-strong dry deposition to... |
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Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00289/40026/39252.pdf |
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