Field evidence for the initiation of isolated aeolian sand patches
arXiv:2302.09895 · doi:10.1029/2022GL101553
Abstract
Sand patches are one of the precursors to early-stage protodunes and occur widely in both desert and coastal aeolian environments. Here we show field evidence of a mechanism to explain the initiation of sand patches on non-erodible surfaces, such as desert gravels and moist beaches. Changes in sand transport dynamics, directly associated with the height of the saltation layer and variable transport law, observed at the boundary between non-erodible and erodible surfaces lead to sand deposition on the erodible surface. This explains how sand patches can form on surfaces with limited sand availability where linear stability of dune theory does not apply. This new mechanism is supported by field observations that evidence both the change in transport rate over different surfaces and in-situ patch formation that leads to modification of transport dynamics at the surface boundary.
References in corpus (12)
- A Continuum Saltation Model for Sand Dunes
- Selection of dune shapes and velocities. Part 1: Dynamics of sand, wind and barchans
- Selection of dune shapes and velocities. Part 2: A two-dimensional modelling
- Flux saturation length of sediment transport
- Field evidence for the upwind velocity shift at the crest of low dunes
- Fluid forces or impacts: What governs the entrainment of soil particles in sediment transport mediated by a Newtonian fluid?
- Elongation and stability of a linear dune
- Direct validation of dune instability theory
- Incipient bedforms in a bidirectional wind regime
- Spatial and temporal development of incipient dunes
- Periodicity in fields of elongating dunes
- Dune initiation in a bimodal wind regime