Bed forms composed of gravel size particles (≈50% >4 mm) are observed in the Wright Valley McMurdo Dry system Antarctica. These bed characterized by a very asymmetrical shape with mean aspect ratio 0.025 (standard deviation 0.005), wavelength 2.7 m (±0.49 m), and height 0.06 (±0.01 m). Particle analysis form sediments shows bimodality peak near 9 mm another between 0.5 0.25 mm. Time‐integrated sediment trap samples horizontal saltation creep flux indicate ≥4 during two‐year monitoring...

Abstract The Oceano Dunes near Pismo Beach, California is part of a large transgressive dune system that extends up to 5 km inland and hosts state park has been managed for off‐highway vehicle recreation since 1982, although activity existed in the dunes almost 90 years. As result, foredunes have largely obliterated sand surfaces use areas are highly emissive dust‐sized particles, causing frequent exceedances air quality standards. To reduce dust emissions from dunes, nature‐based foredune...

Mean wind profiles within a unit-aspect-ratio street canyon have been estimated by solving the three-dimensional Poisson equation for set of discrete vortex sheets. The validity this approach, which assumes inviscid dynamics away from boundaries and small nonlinear contribution to growth turbulent fluctuations, is tested series idealised realistic flows. In paper, effects urban geometry on accuracy are examined with neutral flow over shallow, deep, asymmetric canyons, while thermal...

A measurement campaign was undertaken April–October 2021 using PM10 filter samplers to collect 24 h samples downwind of the Oceano Dunes State Vehicular Recreation Area (ODSVRA), an area that allows off-highway driving on its coastal dunes. The were analyzed and these data used identify sources contributed under varying meteorological conditions. Exposed filters weighed calculate mass concentration X-ray fluorescence quantify elemental composition, ion chromatography water-soluble ions,...

Abstract Wind-driven shear stresses drive saltation and dust emissions over sand dunes. However, the complex topography of coastal dunes practical difficulties in measuring presence blowing make a detailed view this important information difficult to obtain. We combine computational fluid dynamics with field instrumentation high resolution topographic data investigate resulting from on-shore winds on ground surface for flat sloping beach area, nebkha foredune, transverse dune at Oceano...

The Salton Sea in California’s Imperial and Riverside counties is a large endorheic lake with significant areas of exposed shoreline.  shoreline surrounding desert are potential sources wind-blown dust that can contribute to degraded air quality as the emissions create high concentrations particulate matter ≤10 µm aerodynamic diameter (i.e., PM10), which federally regulated pollutant USA.  Sea’s water surface height lowering at an...

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A fast pollutant dispersion model for urban canopies is developed by coupling mean wind profiles to a parameterisation of turbulent diffusion and solving the time-dependent advection–diffusion equation. The performance simplified, coarse-grained representation velocity field investigated. Spatially averaged within local averaging regions or repeating units are predicted three-dimensional Poisson equation set discrete vortex sheets. For each region, parameterised in terms profile using...

The Oceano Dunes State Vehicular Recreation Area (ODSVRA) allows off-highway vehicle (OHV) activity on this coastal dune system. Three sources of data were examined to determine if OHV increased wind-blown dust emissions originating from the ODSVRA. Measurements emissivity (mg m−2 s−1) particulate matter (PM) sands made using PI-SWERL® instrument 2013 through 2020 in area with and areas where access is not permitted. These measurements indicated that mean riding was two three times higher...

Although one-dimensional non-linear diffusion equations are commonly used to model flow dynamics in aquifers and fissures, they disregard multiple effects of real-life flows. Similarity analysis may allow further analytical reduction these equations, but it is often difficult provide applicable initial boundary conditions practice, or know the magnitude neglected by 1D model. Furthermore, when simplifying assumptions made, sources discrepancy between modeled observed data identify. We derive...

The flux of wind-driven dust emissions from a susceptible area is determined by complex relation between the driving force wind and emissivity surface.  This also modulated availability sand-sized particles available for saltation, roughness surface, environmental conditions related to moisture, i.e., soil moisture relative humidity.  (F, µg m-2 s-1) dust-sized surface scales non-linearly with shear stress (τ, N m-2, or velocity u*, m s-1...

Advances in wildfire modeling have focused on refining atmospheric interactions for obvious links between local airflows, combustion dynamics, fire line advance and smoke plume transport. Yet, lasting impacts of wildfires landscapes are linked primarily with changes soil characteristics alteration ecological hydrologic processes. Quantitative assessment requires metrics fire-surface thermal beyond qualitative surrogates such as burn severity used assessment. The highly transient localized...