Long-term frequency and characteristics of dust storm events in Northeast Iceland (1949-2011)

摘要

Long-term records of meteorological dust observations from Northeast Iceland were analysed and frequency of dust events from Icelandic deserts calculated. A total of 1033 dust days were reported during the period 1949-2011 with an annual mean of 16.4 dust days year~(-1) placing the area among the dustiest areas in the world. The most active decades were the 2000s, 1990s and 1950s. Monthly dust event frequency is bimodal with primary and secondary maxima in June and September. A total of 14 severe dust storms (visibility < 500 m) occurred during the period. Median dust event concentration was calculated as 106 μg m~3 from the visibility observations. The frequency and severity of dust events depend on Sea Level Pressure (SLP) oscillation which controls the southerly winds in NE Iceland. The availability of fine sediments susceptible to dust production in outwash plains controlled by the flow rate of glacial river is also important. Volcanic ash from eruptions in 2010 and 2011 barely affected the dust event frequency in NE Iceland. Icelandic dust may be substantial source for large scale air pollution in the Arctic.