Work

Multiscale Coupling of Boundary Layer Flow Turbulence and Sand Streamer Dynamics

Year: 2026

Type: article

Abstract: Wind‐driven sand transport at the Earth's surface exhibits pronounced spatiotemporal variability, forming elongated sand streamers that critically control sand flux. Despite their importance, the detailed fundamental mechanisms governing streamer formation remain elusive. This study presents results from a novel image‐processing algorithm analyzing high‐resolution video imagery combined with 3D wind measurement in turbulent boundary layer flow over a sandy beach. Streamers are shown to align with high‐momentum pathways modulated by large‐scale turbulence structures, and sand flux inside streamers scales with flow forcing. Streamer width remains invariant and decoupled from flow forcing, whereas streamer spacing increases with wind speed. These results support a top‐down modulation mechanism where the invariant streamer width is likely governed by the height of the turbulent footprint, whereas the increased spacing may relate to spanwise dilation of vortex scales or a near‐surface momentum feedback mediated by the saltating sand.

Source: Geophysical Research Letters

DOI: 10.1029/2025gl121555

Authors: Mengdi Yan, Yuanwei Lin, Yang Zhang, Andreas C. W. Baas

Institutions: Xi'an Jiaotong University, King's College London

Language: English

Topic: Aeolian processes and effects

Subfield: Earth-Surface Processes

Field: Earth and Planetary Sciences

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,190

Funder: Natural Environment Research Council