Tracer techniques in aeolian research: Approaches, applications, and challenges

Aeolian processes, the entrainment, transport and deposition of sediments by wind, impacts climate, biogeochemical cycles, food security, environmental quality and human health. Considering the multitude of interactions between aeolian processes and all the major components of the Earth system, there is a growing interest in the scientific community to quantify the wind-related sediment movement process and redistribution rates at different spatial and temporal scales. However, this quantification is rather challenging, due to the complexities of physical mechanisms involved in aeolian processes and the inherent fundamental differences from the rather well-studied processes controlling fluvial erosion. Traditional techniques, such as erosion plots and surveying methods for monitoring wind erosion, are capable of quantifying sediment movement on small scales but they have a number of limitations in terms of the representativeness of the data obtained, spatial and temporal resolution and the patterns over extended areas, and the costs involved. The demand for alternative methods of soil loss and sediment redistribution assessment, in order to complement and enhance the existing methods, has directed attention to use tracing approaches for monitoring rates and spatial patterns of sediment redistribution at various scales. A comprehensive synthesis of available information from different scientific disciplines on aeolian tracer techniques, their applications and limitations are important in understanding the role of aeolian processes and their interactions with the Earths systems in changing climate and management scenarios. The objective of this paper is to provide a scientific review of the current tracer approaches in aeolian studies, including fallout radionuclides, rare earth elements, sediment finger printing and soil magnetism, as well as giving an introduction of the potential tracers that are in development.