Chemical Composition of Atmospheric Aerosol in Asian Dust Events Measured at Whistler Peak 2002-2008
Abstract
Measurements of atmospheric aerosols have been made at the Peak of Whistler Mountain on Canada’s West coast since March 2002. Particles were collected on filter packs with a 2.5 micron size cut on a 24 or 48 hour schedule and analyzed for inorganic species. Particle size distributions from 10 nm to 10 microns were measured with a combination of an optical particle counter and a differential mobility analyzer. Dust events from spring 2002-2008 are identified both from the particle physical measurements and by using calcium as an indicator for soil dust. With few exceptions, higher sulphate was found in these dust events implying a coincident transport of pollution with the dust. During the spring 2006 INTX-B campaign, particles were also sampled using MOUDI impactors and size-segregated samples were analyzed both for standard inorganics by ion chromatography and for an elemental analysis by ICP-MS. A substantial fine mode was found during the Asian dust events with the sulphate confirmed in both the submicron and the supermicron aerosol. Although coarse mode sulphate was associated with calcium, it was independent of calcium in the fine mode. The fine and coarse fractions of elements such as lead, associated with anthropogenic pollution, and of iron, mostly associated with soil dust in this case, suggst dust scavenging of anthropogenic particles.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFM.A13B0226M
- Keywords:
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- 0305 ATMOSPHERIC COMPOSITION AND STRUCTURE / Aerosols and particles;
- 0365 ATMOSPHERIC COMPOSITION AND STRUCTURE / Troposphere: composition and chemistry;
- 0368 ATMOSPHERIC COMPOSITION AND STRUCTURE / Troposphere: constituent transport and chemistry