Gunn, Andrew1, Lancaster, Nicholas2, Edmonds, Douglas3, Ewing, Ryan4, Jerolmack, Douglas1
1University of Pennsylvania, Philadelphia, United States, 2Desert Research Institute, Reno, United States, 3Indiana University, Bloomington, United States, 4Texas A&M University, College Station, United States
Wind-blown sand dunes are both a consequence and a driver of climate dynamics; they arise under persistently dry and windy conditions, and are sometimes a source for airborne dust. Dune fields experience extreme daily changes in temperature, yet the role of atmospheric stability in driving sand transport and dust emission has not been established. Here we report on an unprecedented multi-scale field experiment at the White Sands Dune Field (New Mexico, USA), where we demonstrate that a daily rhythm of sand and dust transport arises from non-equilibrium atmospheric boundary layer convection. A global analysis of 45 dune fields, including those in Australia, confirms the connection between surface wind speed and diurnal temperature cycles, revealing an unrecognized land-atmosphere feedback that may contribute to the growth of deserts on Earth and dune activity on Mars.
Andrew Gunn is a PhD candidate in Earth & Environmental Sciences at the University of Pennsylvania advised by Prof. Douglas Jerolmack. His dissertation is on aeolian process geomorphology. He completed his undergraduate at the University of Melbourne in Applied Mathematics, and Honours at the University of Tasmania in Physical Oceanography.