Substantial contribution of northern high-latitude sources to mineral dust in the Arctic

Author(s)
C. D. Groot Zwaaftink, H. Grythe, H. Skov, A. Stohl
Abstract

In the Arctic, impurities in the atmosphere and cryosphere can strongly affect the atmospheric radiation and surface energy balance. While black carbon has hence received much attention, mineral dust has been in the background. Mineral dust is not only transported into the Arctic from remote regions but also, possibly increasingly, generated in the region itself. Here we study mineral dust in the Arctic based on global transport model simulations. For this, we have developed a dust mobilization scheme in combination with the Lagrangian particle dispersion model FLEXPART. A model evaluation, based on measurements of surface concentrations and annual deposition at a number of stations and aircraft vertical profiles, shows the suitability of this model to study global dust transport. Simulations indicate that about 3% of global dust emission originates from high-latitude dust sources in the Arctic. Due to limited convection and enhanced efficiency of removal, dust emitted in these source regions is mostly deposited closer to the source than dust from for instance Asia or Africa. This leads to dominant contributions of local dust sources to total surface dust concentrations (~85%) and dust deposition (~90%) in the Arctic region. Dust deposition from local sources peaks in autumn, while dust deposition from remote sources occurs mainly in spring in the Arctic. With increasing altitude, remote sources become more important for dust concentrations as well as deposition. Therefore, total atmospheric dust loads in the Arctic are strongly influenced by Asian (~38%) and African (~32%) dust, whereas local dust contributes only 27%. Dust loads are thus largest in spring when remote dust is efficiently transported into the Arctic. Overall, our study shows that contributions of local dust sources are more important in the Arctic than previously thought, particularly with respect to surface concentrations and dust deposition.

Organisation(s)
Department of Meteorology and Geophysics
External organisation(s)
Norwegian Institute for Air Research, Stockholm University, Finnish Meteorological Institute, Aarhus University
Journal
Journal of Geophysical Research
Volume
121
Pages
13,678-13,697
ISSN
0148-0227
DOI
https://doi.org/10.1002/2016JD025482
Publication date
11-2016
Peer reviewed
Yes
Austrian Fields of Science 2012
105206 Meteorology
ASJC Scopus subject areas
Geophysics, Oceanography, Forestry, Aquatic Science, Ecology, Water Science and Technology, Soil Science, Geochemistry and Petrology, Earth-Surface Processes, Atmospheric Science, Space and Planetary Science, Earth and Planetary Sciences (miscellaneous), Palaeontology
Portal url
https://ucrisportal.univie.ac.at/en/publications/09033ed1-b95e-4ee7-8cf5-86661f90d974