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 multiscale field experiment at the White Sands Dune Field (New Mexico, USA), where by measuring wind, humidity and temperature profiles in the atmosphere concurrently with sediment transport, we demonstrate that a daily rhythm of sand and dust transport arises from nonequilibrium atmospheric boundary layer convection. A global analysis of 45 dune fields confirms the connection found in situ between surface wind speed and diurnal temperature cycles, revealing an unrecognized climate feedback that may contribute to the growth of deserts on Earth and dune activity on Mars.
- atmospheric boundary layer
- dune fields