Aeolian system responses to global change: challenges of scale, process and temporal integration

Abstract

Aeolian sediment systems are extensive components of the Earth's surface -not just in today's active desert environments, but in coastal locations and as presently stable loess and peri-desert ergs. All these systems are subject to potentially significant 21st century changes in dynamics due to global warming impacts on atmospheric circulation, sediment moisture and vegetation cover. But do we know enough in the critical areas of science to allow robust models of likely future dynamics to be developed? Since the establishment of 'modern' aeolian science, research has largely taken two divergent routes: (1) small-scale investigations of the processes of wind shear, sediment entrainment and transportation; and (2) landform and landscape analyses, with bedform systems described and relationships to circulation explained. An intermediate, sedimentological, route has generated attempts towards a more integrated understanding of system behaviour at a range of scales. Four recent developments provide the potential for more robust multiscale integrations of aeolian system behaviour. These are: (1) advances in empirical measurement that allow wind power and sediment flux relations to be better described; (2) modelling of dune and dust dynamics and interactions with key controls; (3) monitoring systems that allow high-resolution observations of sediment flux variations to be recognized and aeolian deposit structures to be understood; and (4) chronometric advances that permit the assessment of the frequency and drivers of dune system activity in the past. We explore and analyse these methodological advances and their potential contribution to the multiscale integrations that are essential for better informed predictions of future global aeolian system dynamics, considering whether the integration of these advances in reductionist and holistic elements of aeolian science represent an example of the effective application of the principles of Earth system science.

Spatial analysis of sand dunes with a new global topographic dataset: new approaches and opportunities

“…Recent research articles and reviews suggest that dune pattern analysis and numerical modeling are providing signifi cant contributions to the understanding and interpretation of dune systems (Werner, 1999(Werner, , 2003Kocurek and Ewing, 2005;Baas, 2007;Tooth, 2007;Livingstone et al, 2007;Thomas and Wiggs, 2008;Murray et al, 2009). In both research domains, which are complimentary and overlapping, opportunities to integrate topographic data such as the ASTER GDEM are numerous.…”

Extraterrestrial dunes: An introduction to the special issue on planetary dune systems

“…Investigations on Earth have used field surveys and experiments, in combination with aerial and satellite images, to identify basic types of dune and the processes that form them; and to trace the origins of the sediments (for reviews see Pye and Tsoar, 1990;Lancaster, 1995;Livingstone et al, 2007;Thomas and Wiggs, 2008). Such studies provide a baseline for comparative analyses of dunes on other planetary bodies.…”

The influence of different environmental and climatic conditions on vegetated aeolian dune landscape development and response

“…Climate change has the ability to alter hydrological conditions, modifying both climate variability and moisture availability (Overpeck and Cole, 2006), which affect vegetation growth. It is likely that future changes in climate will create the conditions necessary to activate or stabilise large areas of sensitive aeolian environments and modelling can help indicate possible future trends (Thomas and Wiggs, 2008;Viles et al, 2008) and explain historical system dynamics.…”