Aeolian dust is an important component of the earths surface materials and plays an important role in global environmental change. Aeolian dust deposition can provide valuable scientific information on a variety of phenomena including climate change, vegetation evolutionary history, atmospheric chemistry and atmospheric circulation.
Aeolian dust deposition (ADP) is the process in which wind-blown material – dust, silt, and clay particles –are deposited on the surface of a landscape. Aeolian dust primarily originates from arid and semi-arid regions, with desert surfaces and areas exposed by erosional unloadingproviding the largest available sources. Other potential sources of aeolian dust include human activities such as construction and land-use change. Aeolian processes then transport dust from its source area to areas downwind, located both in the same region (local-scale deposition) or elsewhere in the world (global-scale deposition).
The intensity of aeolian dust deposition depends on various factors including the availability of dust source areas, the strength of wind and the height of wind-driven dust plumes. Dust sources like deserts are abundant in arid and semi-arid regions of the world, where aeolian dust is regularly deposited on, and accumulates in, soils, surface water and sediments. Thus, the amount of dust deposited, and the speed of deposition, varies regionally and seasonally, reflecting the availability and movement of dust sources, as well as the strength of winds around the circumglobal expanses. At larger, global scales, dust deposition can generally be traced back to specific source areas, with Antarctica and North Africa as the two major global sources of dust.
Aeolian dust deposition is an important component of soil formation processes, as some of the deposited dust affixes to bare soils, forming a layer of dust called loess. Depending on their composition, the amount of dust that is deposited and the intensity of wind erosion, dusty areas accumulate distinct loess deposits. Aeolian dust deposition can also provide micronutrients and serve as a carbon sink. The effective diffusion of fertilizer, water management and soil conditioning can be enhanced through the use of aeolian dust deposition.
Interpreting the past record of aeolian dust deposition can provide information on a range of environmental and climate change processes. Increasing concentrations of dust in the atmosphere has been connected with global warming, as dust can reduce the amount of incoming solar radiation and thus cool the climate. Conversely, decreased dust deposition has been linked with cooling of the climate, due to increases in incoming solar radiation. By reconstructing the history of dust deposition, as revealed by natural archives such as glacial ice, lake sediments and marine deposits, it is possible to gain insight into past climate variability. Moreover, changes in aeolian dust deposition can be used to track and quantify past changes in winds, which in turn can provide information on past atmospheric circulation, desertification and drought.
The use of aeolian dust deposition as a tool to interpret environmental records has become increasingly popular in the past decades. The ability to interpret past records of air quality, as well as climate changes, has been greatly enhanced with the application of chemical and isotopic analysis techniques such as noble gas geochemistry and Antarctic ice core analyses.
Aeolian dust deposition has also been applied to interpret terrestrial postglacial climate change. In terrestrial settings, lakes, peats, soils and archaeological sites can serve as valuable archives of postglacial climate change. Aeolian dust can be used to reconstruct landscape changes, from the establishment of aeolian dust depositional areas (called Loess Plateaus), to the extent of soil erosion and other physical factors. In addition, record
