A wind-albedo-wind feedback driven by landscape evolution

Area of Science:

• Climate Science
• Atmospheric Science
• Geomorphology

Background:

• Accurate characterization of near-surface winds is critical for understanding past and modern climate.
• Dust lofted by winds significantly influences surface, atmospheric, and ocean conditions.
• Stony deserts, currently low dust emitters, are sensitive to geological changes impacting near-surface conditions.

Purpose of the Study:

• To investigate the relationship between wind-driven landscape evolution and atmospheric boundary layer conditions.
• To demonstrate a previously undocumented feedback mechanism in desert environments.
• To quantify the impact of altered surficial geology on near-surface wind speeds.

Main Methods:

• Utilized the Weather Research and Forecasting (WRF) model for simulations.
• Focused analysis on the western Gobi Desert region.
• Examined changes in surficial thermal properties and albedo due to sediment winnowing and gravel mantle formation.

Main Results:

• Altered surficial thermal properties led to an increase in near-surface winds by up to 25%.
• Demonstrated a paradoxical effect where wind erosion results in regionally faster winds.
• Observed an increased frequency of high wind speed hours, suggesting heightened dust emission potential.

Conclusions:

• A novel wind-albedo-wind feedback mechanism was identified.
• Landscape evolution in stony deserts can significantly amplify near-surface wind speeds.
• These findings have critical implications for understanding dust emission dynamics and climate feedbacks.