EGU2020-182
https://doi.org/10.5194/egusphere-egu2020-182
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Proto-dune formation under a bimodal wind regime

Pauline Delorme1, Giles Wiggs2, Matthew Baddock3, Joanna Nield1, James Best4, Kenneth Christensen5, Nathaniel Bristow5, Andrew Valdez6, and Philippe Claudin7
Pauline Delorme et al.
  • 1School of Geography and Environmental Science, University of Southampton, Southampton, UK (p.m.t.delorme@soton.ac.uk)
  • 2School of Geography and the Environment, University of Oxfrod, Oxford, UK
  • 3Geography and Environment, Loughborough University, Loughborough, UK
  • 4Departement of Geology, University of Illinois at Urbana-Champaign, Champaign, Illinois, USA
  • 5Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana, USA
  • 6National Park Service - NPS - Great Sand Dunes National Park & Preserve, Mosca, Colorado, USA
  • 7Laboratoire de Physique et Mecanique des Milieux Heterogenes, ESPCI - CNRS - PSL Research University – Univ.Paris-Diderot – Sorbonne Universite, Paris, France

Early-stage aeolian bedforms develop into sand dunes through complex interactions between flow, sediment transport and surface topography. Depending on the specific environmental and wind conditions the mechanisms of dune formation, and ultimately the shape of the nascent dunes, may differ. Here, we investigate the formation of a proto-dune-field, located in the Great Sand Dunes National Park ( Colorado, USA), using a three dimensional linear stability analysis.

We use in-situ measurements of wind and sediment transport, collected during a one-month field campaign, as part of a linear stability analysis to predict the orientation and wavelength of the proto-dunes.

We find that the output of the linear stability analysis compares well to high-resolution Digital Elevation Models measured using terrestrial laser scanning. Our findings suggest that the bed instability mechanism is a good predictor of proto-dune development on sandy surfaces with a bimodal wind regime.

How to cite: Delorme, P., Wiggs, G., Baddock, M., Nield, J., Best, J., Christensen, K., Bristow, N., Valdez, A., and Claudin, P.: Proto-dune formation under a bimodal wind regime, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-182, https://doi.org/10.5194/egusphere-egu2020-182, 2019

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