Mineral Dust Dynamics and Climate Change
at High Latitude Mountainous Regions
Principal Investigator: James King (University of Montréal)
Opportunity: Atmospheric aerosols are a complex mixture of inorganic and organic components and can range in size from a few nanometers to several micrometers. An important fraction of the total global aerosol budget is mineral dust (MD) aerosols, which augment the atmospheric radiation budget directly, by reflecting or absorbing solar radiation, and indirectly, by acting as cloud condensation or ice nuclei. This alters cloud properties such as albedo, lifetime and the quantity of precipitation. Once deposited, MD can behave like a black body, disproportionately enhancing the melting of snow surfaces, as well as providing essential nutrients to ecosystems. No data on Canada’s total annual emissions are currently available despite a global estimate of 80-100 Tg per year of MD aerosols from high latitude sources.
Objectives: The team will investigate the influence of MD from mountainous regions on surrounding ecosystems through a series of projects that culminate in providing results to better understand the ecological impacts and radiative impacts of MD, as well as to increase the current capacity to model the changes in landscape and MD emissions under future climate change scenarios. The research objectives are to: (1) Identify the mechanisms that produce pro-glacial valley wind erosion; (2) Characterize physical, optical and chemical properties of airborne and deposited mineral dust at high latitudes; (3) Evaluate the importance of nutritional inputs provided from mineral dust deposition onto surrounding landscapes; and (4) Develop and evaluate dust production models for high latitude regions.
Research Plan: A combination of intensive field measurements, remote sensing analyses, climate model development, and paleoclimate reanalysis, will provide the basis to meet the objectives of the proposed research. The field campaigns will be conducted in the southern limit of historical dust deposited soils at Łhù’ààn Mân (Kluane Lake), YT, providing a glacial history of MD deposition rates and a recent dramatic increase in the effects of climate change through a complete change in the river drainage increasing present-day MD emission frequency. Partnerships with indigenous community groups will facilitate the ranking of objectives and milestone timing, while the partnerships with Parks Canada and the Yukon Government will facilitate the integration of the proposed methodology with currently ongoing research on lake ecosystem functions.
Key Outcomes & Impact: This researcher-led, partnership-assisted, and indigenous community-supported project will identify and quantify the climatic variables that control dust emissions from mountainous regions, integrate them into a new dust production model to inform Environment Canada’s current global climate model (CanAM4) for its emission and transport of MD aerosols, and evaluate the current and historical impacts of the deposited MD aerosols on surrounding polar landscapes.
Other Team Members:
Daniel Fortier (University of Montréal), Thora Herrmann (University of Montréal), Patrick Hayes (University of Montréal), Daniel Nadeau (University of Laval), Norman O’Neill (University of Sherbrooke), Julie Talbot (University of Montréal)