Characterisation of individual airborne particles by using aerosol time-of-flight mass spectrometry (ATOFMS) at Mace Head, Ireland,
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Date
2004Author
Dall'Osto, Manuel
Beddows, David C S
Kinnersley, Robert P
Harrison, Roy M
Donovan, Robert J
Heal, Mathew R
Metadata
Abstract
An aerosol time-of-flight mass spectrometer was deployed at Mace Head
(Ireland) during August 2002. The measurements provide qualitative chemical
composition and size distribution (0.3–3 μm) information for single particles. Three
broad categories of particles: sea salt, dust, and carbon-containing particles were
identified and apportioned, and their temporal evolution (1 hour resolution) is
described. Aerosol sources were correlated with meteorological factors and with air
mass trajectories, demonstrating long-range transport of different continental air
masses from Europe, Africa, and America. The major class of particles was derived
from sea salt and was subdivided into pure, mixed, and aged sea salt according to the
extent of displacement of chloride by nitrate. Two types of dust particles were found
mainly in the coarse mode (>1 μm); the former, thought to originate from the Sahara,
presented an aluminium/silicon signature, while the latter, of more local origin, had a
calcium-rich composition. Carbon-containing particles were mainly distributed in the
fine mode (<1 μm) and associated with different chemical species in different size
modes, suggesting different mechanisms of formation.