%0 Journal Article
%T Seasonal Variation of the Aerosol Light Scattering Coefficient in Marine Air of the Northeast Atlantic
%A Aditya Vaishya
%A S. G. Jennings
%A Colin O'Dowd
%J Advances in Meteorology
%D 2011
%I Hindawi Publishing Corporation
%R 10.1155/2011/170490
%X Aerosol light scattering measurements were carried out using a TSI 3563 Nephelometer at the Mace Head Atmospheric Research Station, on the west coast of Ireland from year 2001–2010. A strong seasonal trend in the aerosol light scattering coefficient at 550 nm (scat), for clean marine air masses, is observed with a high scat value, [average (geometric mean)] of 35.3 Mm−1 (29.5 Mm−1), in January and a low scat value of 13.7 Mm−1 (10.2 Mm−1), in July. This near threefold increase in the scat value during the winter season is because of the large contribution of wind-speed generated sea-salt particles in the marine boundary layer. A high positive correlation coefficient of 0.82 was found between the percentage occurrence of relatively large Ångström exponent (Å) values (>1.2) and the percentage occurrence of lower scat values (5–15 Mm−1) in the summer season. scat and wind-speed have a high positive correlation coefficient of 0.88 whereas Å and wind-speed have a negative correlation coefficient of −0.89. Å values during the summer months indicate the dominance of sub-m particles thus indicating the contribution of non-sea-salt sulphate and organics towards the scat as these species show an enhanced concentration during the summer months.
%U http://www.hindawi.com/journals/amet/2011/170490/