%0 Journal Article
%T Volcanic Ash versus Mineral Dust: Atmospheric Processing and Environmental and Climate Impacts
%A Baerbel Langmann
%J ISRN Atmospheric Sciences
%D 2013
%R 10.1155/2013/245076
%X This review paper contrasts volcanic ash and mineral dust regarding their chemical and physical properties, sources, atmospheric load, deposition processes, atmospheric processing, and environmental and climate effects. Although there are substantial differences in the history of mineral dust and volcanic ash particles before they are released into the atmosphere, a number of similarities exist in atmospheric processing at ambient temperatures and environmental and climate impacts. By providing an overview on the differences and similarities between volcanic ash and mineral dust processes and effects, this review paper aims to appeal for future joint research strategies to extend our current knowledge through close cooperation between mineral dust and volcanic ash researchers. 1. Introduction Volcanic ash represents a major product of volcanic eruptions [1¨C3]. It is formed by fragmentation processes of the magma and the surrounding rock material of volcanic vents [1, 4]. Depending on the strength of a volcanic eruption, volcanic ash is released into the free troposphere or even the stratosphere [1, 5], where it is transported by the prevailing winds until it is removed from the atmosphere by gravitational settling and wet deposition [6]. Volcanic ash is also known to be mobilised by wind from its deposits [7¨C12], which have accumulated after volcanic eruptions on land located along the main transport directions of the volcanic cloud, which spreads out over hundreds to thousands of kilometres, dependent on wind speed, ash size, ash density, and eruption magnitude. In contrast to atmospheric mineral dust, the importance of volcanic ash for climate has long been considered negligible [5]. The global mineral dust cycle and its interactions with the Earth¡¯s climate system have been studied widely [13¨C18]. Mineral dust aerosols affect the radiative forcing of the atmosphere directly [13, 19] and indirectly by acting as cloud condensation or ice nuclei [20, 21]. Furthermore, mineral dust aerosols influence ozone photochemistry [22, 23] and supply nutrients to marine [24] and terrestrial ecosystems [25]. Vice versa, climate variability affects the mineral dust burden of the atmosphere through modifications of precipitation, vegetation cover, and wind [15]. This review contrasts the environmental and climatic effects of volcanic ash versus those of mineral dust. A stronger focus is put on the description of volcanic ash, whereas mineral dust effects are described in less detail, but with referencing the extensive literature. Similarities and differences will be
%U http://www.hindawi.com/journals/isrn.atmospheric.sciences/2013/245076/