Insulation effects of Icelandic dust and volcanic ash on snow and ice

• Published in: Arabian Journal of Geosciences
• Main Authors: Dragosics, Monika, Meinander, Outi, Jonsdottir, Tinna, Durig, Tobias, De Leeuw, Gerrit, Palsson, Finnur, Dagsson-Waldhauserova, Pavla, Thorsteinsson, Throstur
• Other Authors: Department of Physics
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer-Verlag 2017
• Subjects: Iceland; Insulation; Ash; Dust; Snow; Albedo; LIGHT-ABSORBING IMPURITIES; DEPOSITION; ERUPTION; 114 Physical sciences; 1171 Geosciences; Arctic; Eyjafjallajokull; albedo; glacier
• Online Access: http://hdl.handle.net/10138/212582

In the Arctic region, Iceland is an important source of dust due to ash production from volcanic eruptions. In addition, dust is resuspended from the surface into the atmosphere as several dust storms occur each year. During volcanic eruptions and dust storms, material is deposited on the glaciers where it influences their energy balance. The effects of deposited volcanic ash on ice and snow melt were examined using laboratory and outdoor experiments. These experiments were made during the snow melt period using two different ash grain sizes (1 phi and 3.5 phi) from the Eyjafjallajokull 2010 eruption, collected on the glacier. Different amounts of ash were deposited on snow or ice, after which the snow properties and melt were measured. The results show that a thin ash layer increases the snow and ice melt but an ash layer exceeding a certain critical thickness caused insulation. Ash with 1 phi in grain size insulated the ice below at a thickness of 9-15 mm. For the 3.5 phi grain size, the insulation thickness is 13 mm. The maximum melt occurred at a thickness of 1 mm for the 1 phi and only 1-2 mm for 3.5 phi ash. A map of dust concentrations on Vatnajokull that represents the dust deposition during the summer of 2013 is presented with concentrations ranging from 0.2 up to 16.6 g m(-2). Peer reviewed