Open AccessCharacterization of aerosols at a coastal site near Vindeby (Denmark)
Author(s) -
Vignati Elisabetta,
Leeuw Gerrit,
Schulz Michael,
Plate Elke
Publication year - 1999
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/1998jc900019
Subject(s) - aerosol , advection , environmental science , atmospheric sciences , troposphere , sea salt , particle (ecology) , fetch , wind speed , chemical composition , meteorology , oceanography , chemistry , geology , physics , organic chemistry , thermodynamics
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 − , SO 4 −− , NO 3 − , and NH 4 + . 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.