Coupling of surface temperature and wind speed in modulating saltation and particle clustering in wind-blown sand transport

Surface temperatures are extremely high during the day in arid and semi-arid regions, yet the impact of this temperature on wind-blown sand dynamics is often overlooked. This study explores the role of surface heat flux in shaping turbulence characteristics and sand transport behaviors through a three-dimensional coupled model. By simulating clean air flow and sand-laden conditions at different surface temperatures, the study reveals how thermal effects influence turbulence intensity, sand transport intermittency, and particle clustering. The results highlight that higher surface temperatures intensify the turbulence, leading to more frequent and sustained fluctuations in sand transport rates, with extreme temperatures (above 330 K) triggering large-scale and long-duration transport events. Furthermore, the strong negative correlation between surface temperature and particle concentration is more pronounced than that between wind speed and particle concentration. However, as height increases, the influence of temperature gradually decreases, while the effect of wind speed shifts from a strong negative correlation to a weak positive correlation. This study offers novel insights into the dual modulation of wind-blown sand transport by surface temperature and wind speed, highlighting their distinct effects. These findings offer new insights into the complex interaction between surface temperature, wind speed, and particle motion, with implications for improving wind erosion control strategies.