Chemical and microphysical properties of wind-blown dust near an actively retreating glacier in Yukon, Canada

• Main Authors: Bachelder, Jill, Cadieux, Marie, Liu-Kang, Carolyn, Pérrine Lambert, Filoche, Alexane, Galhardi, Juliana Aparecida, Hadioui, Madjid, Chaput, Amélie, Bastien-Thibault, Marie-Pierre, Wilkinson, Kevin J., King, James, Hayes, Patrick L.
• Format: Text
• Language: unknown
• Published: Taylor & Francis 2019
• Subjects: 59999 Environmental Sciences not elsewhere classified; FOS Earth and related environmental sciences; 39999 Chemical Sciences not elsewhere classified; FOS Chemical sciences; Ecology; FOS Biological sciences; Arctic; Yukon; Canada; Slims River; glacier*
• Online Access: https://dx.doi.org/10.6084/m9.figshare.9999362.v1; https://tandf.figshare.com/articles/Chemical_and_microphysical_properties_of_wind-blown_dust_near_an_actively_retreating_glacier_in_Yukon_Canada/9999362/1

Airborne mineral aerosols emitted in high-latitude regions can impact radiative forcing, biogeochemical cycling of metals, and local air quality. The impact of dust emissions in these regions may change rapidly, as warming temperatures can increase mineral dust production and source regions. As there exists little research on mineral dust emissions in high-latitude regions, we have performed the first study of the physico-chemical properties of mineral dust emitted from a sub-Arctic proglacial dust source, using a method tailored to the remote conditions of the Canadian North. Soil and aerosol samples (PM 10 and deposited mineral dust) were collected in May 2018 near the Ä’äy Chù (Slims River), a site exhibiting strong dust emissions. WHO air quality thresholds were exceeded at several receptor sites near the dust source, indicating a negative impact on local air quality. Notably, temporally averaged particle size distributions of PM 10 were very fine as compared to those measured at more well-characterized, low-latitude dust sources. In addition, mineralogy and elemental composition of ambient PM 10 were characterized; PM 10 elemental composition was enriched in trace elements as compared to dust deposition, bulk soil samples, and the fine soil fractions (d 10, dust deposition, and both fine and bulk soil fractions, as well as of meteorological factors measured during our campaign, we propose that the primary mechanisms for dust emissions from the Ä’äy Chù Valley are the rupture of clay coatings on particles and/or the release of resident fine particulate matter. Copyright © 2019 American Association for Aerosol Research