Articles | Volume 14, issue 24
Atmos. Chem. Phys., 14, 13411–13422, 2014

Special issue: Interactions between climate change and the Cryosphere: SVALI,...

Atmos. Chem. Phys., 14, 13411–13422, 2014

Research article 16 Dec 2014

Research article | 16 Dec 2014

Long-term variability of dust events in Iceland (1949–2011)

P. Dagsson-Waldhauserova1,2, O. Arnalds1, and H. Olafsson2,3,4 P. Dagsson-Waldhauserova et al.
  • 1Agricultural University of Iceland, Hvanneyri, Borgarnes, Iceland
  • 2University of Iceland, Department of Physics, Reykjavik, Iceland
  • 3Icelandic Meteorological Office, Reykjavik, Iceland
  • 4Bergen School of Meteorology, Geophysical Institute, University of Bergen, Bergen, Norway

Abstract. The long-term frequency of atmospheric dust observations was investigated for the southern part of Iceland and interpreted together with earlier results obtained from northeastern (NE) Iceland (Dagsson-Waldhauserova et al., 2013). In total, over 34 dust days per year on average occurred in Iceland based on conventionally used synoptic codes for dust observations. However, frequent volcanic eruptions, with the re-suspension of volcanic materials and dust haze, increased the number of dust events fourfold (135 dust days annually). The position of the Icelandic Low determined whether dust events occurred in the NE (16.4 dust days annually) or in the southern (S) part of Iceland (about 18 dust days annually). The decade with the most frequent dust days in S Iceland was the 1960s, but the 2000s in NE Iceland. A total of 32 severe dust storms (visibility < 500 m) were observed in Iceland with the highest frequency of events during the 2000s in S Iceland. The Arctic dust events (NE Iceland) were typically warm, occurring during summer/autumn (May–September) and during mild southwesterly winds, while the subarctic dust events (S Iceland) were mainly cold, occurring during winter/spring (March–May) and during strong northeasterly winds. About half of the dust events in S Iceland occurred in winter or at sub-zero temperatures. A good correlation was found between particulate matter (PM10) concentrations and visibility during dust observations at the stations Vík and Stórhöfði. This study shows that Iceland is among the dustiest areas of the world and that dust is emitted year-round.

Short summary
Iceland is an active dust source in the high-latitude cold region. Dust day frequency in Iceland is comparable to dust studies from the active parts of China, Mongolia, and Iran. About 50% of annual dust events in the southern part of Iceland take place at sub-zero temperatures or in winter, when dust may be mixed with snow. The Arctic dust events (NE Iceland) are warm, occurring during summer/autumn while the sub-Arctic dust events (S Iceland) are mainly cold, occurring during winter/spring.
Final-revised paper