Characterization of aerosols at a coastal site near Vindeby (Denmark)

Autor: Elisabetta Vignati, Michael Schulz, Gerrit de Leeuw, E. Plate
Přispěvatelé: TNO Fysisch en Elektronisch Laboratorium
Jazyk: angličtina
Rok vydání: 1999
Předmět:
Zdroj: Journal of Geophysical Research C: Oceans, C2, 104, 3277-3287
Vignati, E, Leeuw, G D, Schulz, M & Plate, E 1999, ' Characterization of Aerosols at a Coastal Site near Vindeby (Denmark) ' Journal of Geophysical Research, vol. 104, no. C2, pp. 3277-3287 .
Popis: Aerosol particle size distributions and aerosol chemical composition were measured with optical particle counters and filter packs, respectively, on an offshore mast in the Danish coastal waters near Vindeby on the island of Lolland. The filter pack samples were analyzed for ions representative of marine and continental aerosol: Na+, Cl-, SC4-, NO3-, and NH4+. The physical and chemical measurements are complementary, and the information on chemical composition, together with the local meteorological parameters, the synoptic situation, and air mass trajectories, is crucial for interpreting the observed variations in the particle concentrations. Considering these sets of data, four periods can be discerned during the experiment. Further, the aerosol concentrations vary with wind speed, as is expected for marine aerosols, depending strongly on the fetch. In the case of short fetch, the coarse aerosol fraction (diameter >1 μm) and the fine aerosol fraction (0.2-1 μm) decrease with wind speed. Processes like advection, diffusion, and dry deposition cannot explain the strong dependence of the concentrations on wind speed. Apparently, uncertainties in the source strength and origin of aerosol advected across the shore line, as well as processes affecting the aerosol concentrations over land, such as variability in the sources, washout by rain, and other removal and transport mechanisms, have much more influence than the transport and removal over water. Copyright 1999 by the American Geophysical Union.
Databáze: OpenAIRE