Dust generation on a proglacial floodplain, West Greenland

Bullard, Joanna E.; Austin, Martin

doi:10.1016/j.aeolia.2011.01.002

Cited by 65 publications

(76 citation statements)

References 53 publications

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“…The amount of dust transport in the tundra of west Greenland is influenced by a lot of complex processes (e.g. Bullard and Austin, 2011) and can change over time. For example, during periods of glacial retreat or during stormy conditions, eolian activity is high.…”

Section: Discussionmentioning

confidence: 99%

Dust from the dark region in the western ablation zone of the Greenland ice sheet

et al. 2011

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Abstract.A dark region tens of kilometres wide is located in the western ablation zone of the Greenland ice sheet. The dark appearance is caused by higher amounts of dust relative to the brighter surroundings. This dust has either been deposited recently or was brought to the surface by melting of outcropping ice. Because the resulting lower albedos may have a significant effect on melt rates, we analysed surface dust on the ice, also called cryoconite, from locations in the dark region as well as locations from the brighter surrounding reference ice with microscopic and geochemical techniques to unravel its composition and origin. We find that (part of) the material is derived from the outcropping ice, and that there is little difference between dust from the dark region and from the reference ice. The dust from the dark region seems enriched in trace and minor elements that are mainly present in the current atmosphere because of anthropogenic activity. This enrichment is probably caused by higher precipitation and lower melt rates in the dark region relative to the ice marginal zone. The rare earth elemental ratios of the investigated material are approximately the same for all sites and resemble Earth's average crust composition. Therefore, the cryoconite probably does not contain volcanic material. The mineralogical composition of the dust excludes Asian deserts, which are often found as provenance for glacial dust in ice cores, as source regions. Consequently, the outcropping dust likely has a more local origin. Finally, we find cyanobacteria and algae in the cryoconite. Total Organic Carbon accounts for up to 5 weight per cent Correspondence to: I. G. M. Wientjes (i.g.m.wientjes@uu.nl) of the cryoconite from the dark region, whereas dust samples from the reference ice contain only 1 % or less. This organic material is likely formed in situ. Because of their high light absorbency, cyanobacteria and the organic material they produce contribute significantly to the low albedo of the dark region.

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Section: Discussionmentioning

confidence: 99%

Dust from the dark region in the western ablation zone of the Greenland ice sheet

et al. 2011

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“…An enrichment in the coarse silt fraction is also supported by the soil samples from Sandflugtdalen (i.e., the most likely primary source area for eolian material in this area) and an eolian deposit found at Two-Boat Lake, where both Zr:Rb and Zr:Ti ratios were higher in the 35-63 μm silt-sized fraction. This higher input of silt-sized mineral particles could come about either as a result of higher wind speeds or-more likely-a larger availability for this type of material, for instance, because of a lake being closer to the primary source areas for silt-size mineral particles-in this case, the glacial outwash plains of Sandflugtdalen (Bullard and Austin, 2011).…”

Section: Discussionmentioning

confidence: 99%

“…This is most evident in the two river valleys, Sandflugtdalen and Ørkendalen, but the whole area is covered by a thick loess deposit, which has largely been stabilized by vegetation (Dijkmans and Törnqvist, 1991;Willemse et al, 2003). The eolian activity is considered to be source limited, and to be highest during the winter months when wind strengths generally are higher (Rott and Obleitner, 1992;Johansson et al, 2015aJohansson et al, , 2015b; however, in winters snow might also decrease the availability of erodible material (Bullard and Austin, 2011).…”

Section: Regional Settingmentioning

confidence: 99%

“…Even if the most pronounced effects of eolian transport are seen in the area close to the source areas in front of the ice sheet, lakes farther away from the ice sheet also will receive eolian input (Dijkmans and Törnqvist, 1991;Bullard and Austin, 2011). From the many wind-erosion scars that are present in the landscape, it is also evident that some redistribution of previously deposited material occurs (Dijkmans and Törnqvist, 1991).…”

Section: Possible Implications Of a High Eolian Input To Lake Ecosystemsmentioning

confidence: 99%

“…An active ice sheet, as well as larger glaciers, produces large amounts of silt-sized mineral particles that can be transported in suspension by wind (Bullard and Austin, 2011). The area around Kangerlussuaq in western Greenland has such a cold and arid climate where eolian transport is an important mechanism for particulate matter transport (Dijkmans and Törnqvist, 1991).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The Importance of Eolian Input on Lake-Sediment Geochemical Composition in the Dry Proglacial Landscape of Western Greenland

Rydberg

Lindborg

Sohlenius

et al. 2016

Arctic, Antarctic, and Alpine Research

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

et al. 2016

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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.

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Dust generation on a proglacial floodplain, West Greenland

Cited by 65 publications

References 53 publications

Dust from the dark region in the western ablation zone of the Greenland ice sheet

Dust from the dark region in the western ablation zone of the Greenland ice sheet

The Importance of Eolian Input on Lake-Sediment Geochemical Composition in the Dry Proglacial Landscape of Western Greenland

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

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