Aerodynamic roughness of rippled beds under active saltation at Earth-to-Mars atmospheric pressures

Carlos A. Alvarez (), Mathieu G. A. Lapôtre, Christy Swann, Ryan C. Ewing, Pan Jia and Philippe Claudin
Additional contact information
Carlos A. Alvarez: Stanford University
Mathieu G. A. Lapôtre: Stanford University
Christy Swann: RCOAST
Ryan C. Ewing: NASA Johnson Space Center
Pan Jia: Harbin Institute of Technology
Philippe Claudin: UMR 7636 CNRS—ESPCI Paris—Université PSL—Université Paris Cité—Sorbonne Université

Nature Communications, 2025, vol. 16, issue 1, 1-9

Abstract: Abstract As winds blow over sand, grains are mobilized and reorganized into bedforms such as ripples and dunes. In turn, sand transport and bedforms affect the winds themselves. These complex interactions between winds and sediment render modeling of windswept landscapes challenging. A critical parameter in such models is the aerodynamic roughness length, z0, defined as the height above the bed at which wind velocity predicted from the log law drops to zero. In aeolian environments, z0 can variably be controlled by the laminar viscous sublayer, grain roughness, form drag from bedforms, or the saltation layer. Estimates of z0 are used on Mars, notably, to predict wind speeds, sand fluxes, and global circulation patterns; yet, no robust measurements of z0 have been performed over rippled sand on Mars to date. Here, we measure z0 over equilibrated rippled sand beds with active saltation under atmospheric pressures intermediate between those of Earth and Mars. Extrapolated to Mars, our results suggest that z0 over rippled beds and under active saltation may be dominated by form drag across a plausible range of wind velocities, reaching values up to 1 cm—two orders of magnitude larger than typically assumed for flat beds under similar sediment transport conditions.

Date: 2025
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/s41467-025-60212-7 Abstract (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:natcom:v:16:y:2025:i:1:d:10.1038_s41467-025-60212-7

Ordering information: This journal article can be ordered from
https://www.nature.com/ncomms/

DOI: 10.1038/s41467-025-60212-7

Access Statistics for this article

Nature Communications is currently edited by Nathalie Le Bot, Enda Bergin and Fiona Gillespie

More articles in Nature Communications from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().