Similarly to the way a river, flowing across Earth's surface, influences sediment transport and shaping of the landscape, so coastal winds, flowing over dunes, affect how the dune shapes evolve and how sand is transported along the coast.
Wind flow over dunes has been extensively studied, but in most cases studies have been two-dimensional and focused on straight dunes with smooth slopes and no vegetation or other features that might affect how airflow separates at the crest of the dune.
To get a more complete picture of the complex flows, Delgado-Fernandez et al. conducted what they believe is the first three-dimensional field study of airflow patterns on the leeward side of a coastal dune.
Over the course of 10 days, the research team used an array of ultrasonic anemometers deployed over a beach-dune surface in Northern Ireland to map the complex wind patterns. The authors compare their findings with previous studies and discuss some possible similarities and differences between airflow patterns in the coastal setting and airflow and water-flow patterns in other environments.
As the movement of sand through wind action can dramatically help beaches and dunes rebuild themselves after erosion by coastal storms, this study could help scientists understand how particular wind events can aid in post-storm recovery of sandy coastlines.
Source:Journal of Geophysical Research-Earth Surface, doi:10.1002/jgrf.20036, 2013, Field characterization of three-dimensional lee-side airflow patterns under offshore winds at a beach-dune system, Authors: Irene Delgado-Fernandez, Derek W.T. Jackson and J.Andrew G. Cooper: Centre for Coastal and Marine Research, School of Environmental Sciences, University of Ulster, Cromore Road, Coleraine, Northern Ireland, UK; Andreas C.W. Baas: Department of Geography, King's College London, Strand, London, UK; J.H.Meiring Beyers: Klimaat Consulting & Innovation Inc., Guelph, Canada; Kevin Lynch: Department of Geography and Archaeology, National University of Ireland, Galway,University Road, Galway, Ireland.