1. Giles Wiggs Sheffield Centre for International Drylands Research Aeolian dune processes and dynamics 2004 Joint Assembly Montreal, Canada

2. Dunes in equilibrium…. Best 1993

3. Measurements of mean windspeed and sediment transport McKenna-Neumann et al 1997 Wiggs 2001 windspeed sand flux

4. Lancaster et al 1996 Measurements of shear velocity U*U* Wiggs 2001 mean shear velocity shear stress turbulence

5. Measurements of Reynolds turbulent stress Reynolds stress Streamline angle

6. Calibration of numerical models Parsons et al 2004

8. Other modelling approaches - complex systems Werner 1995 Momiji et al 2000 Baas 2002

9. Other modelling approaches - analytical solutions ( Hersen, Sauermann, Herrmann, Andreotti) Schwammle & Herrmann 2003 Hersen 2004

10. Hersen et al 2004 Output sand flux Dune width

11. Dunes in dis-equilibrium….? Parker Gay Jr 1999 Hersen 2004

12. Conclusions 1.dune research is in a healthy state! 2.measurements of airflow structure improving BUT requires improved understanding of turbulence / sediment transport relationships 3.calibration of computational models allowing greater understanding of form/flow interactions 4.results of analytical models suggest a requirement for more fieldwork focusing on:  dynamics of sediment transfers at the dune and inter-dune scale  longer time-series measurements of dune evolution