Submicron volcanic dust from the largest desert in Europe and Arctic

Iceland is the largest desert in Europe and Arctic where interactions between the cryosphere and atmosphere are profound. Frequent strong winds make the long-term dust frequency in Iceland, based on the meteorological data from 30 weather stations in period 1949-2011, similar to the major desert areas of the world (Mongolia, Iran, China). Volcanic eruptions with the re-suspension of volcanic materials and dust haze contribute to the number of dust events resulting in 135 dust days annually. The in situ measurements showed that suspended volcanic dust in Iceland causes air pollution with extremely high PM1 concentrations comparable to the polluted urban stations in Europe or Asia than reported dust event observations from around the world. The PM1/PM2.5 ratios are generally low during dust storms outside of Iceland, much lower than > 0.9 and PM1/PM10 ratios of 0.34-0.63 found in our study. It shows that Icelandic volcanic dust consists of higher proportion of submicron particles compared to crustal dust. The submicron particles are predicted to travel long distances. Moreover, such submicron particles pose considerable health risk because of high potential for entering the lungs. Icelandic volcanic glass has often fine pipe-vesicular structures known from asbestos and has high content of heavy metals. Satellite images revealed dust plumes >1,000 km from Iceland, towards the Arctic and Europe (MODIS). Optical properties of Icelandic volcanic dust have been found similar to black carbon. Icelandic volcanic dust have negative effects on air quality and reduce visibility.