On the Wind Erosion of Small Particles 1

Hilst, Glenn R.; Nickola, P.W.

doi:10.1175/1520-0477-40.2.73

Cited by 7 publications

(3 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The friction area (the size) of the grain affects the magnitude of its mean velocity during creep. If u c is not affected by u * and remains stable during creep, some other mechanism must be responsible for suddenly turning creep into saltation (for example, the inclined plane; Hiest & Nichola, ). This feature can effectively distinguish creep from saltation, which is surrounded and continuously accelerated by an air flow.…”

Section: Resultsmentioning

confidence: 99%

Measurement of sand creep on a flat sand bed using a high‐speed digital camera: Mesoscopic features of creeping grains

et al. 2015

View full text Add to dashboard Cite

The characterization of aeolian sand creep motion remains incomplete. In this study, a top-view imaging system was constructed in a wind tunnel experiment to record sand creep motion on a flat sand bed. In addition, a set of 'mesoscopic' parameters was defined based on the creep trajectory that was reconstructed by a particle tracking algorithm. Statistical results show that the parameters representing the lifespan of the creep motion follow a lognormal distribution, whereas those representing the sideways grain motion deviate from the lognormal distribution. As the wind velocity increases, the sideways motion is strengthened and the lifespan of the creep motion is shortened, indicating a stronger transition from creep to saltation. Furthermore, under a 'pure rolling' hypothesis, the creep trajectory can be transformed into two numbers of rolling cycles from the perspectives of space and time. The ratio of the two numbers is useful in identifying the specific mode of the creep motion.

show abstract

Section: Resultsmentioning

confidence: 99%

Measurement of sand creep on a flat sand bed using a high‐speed digital camera: Mesoscopic features of creeping grains

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Additional natural terrestrial sources of particulates and aerosols include the weathering of geological materials to produce soil particulates at the surface, the effects of wind erosion (Hilst and Nickola, 1959), the formation of aerosol particles derived from naturally occurring hydrocarbons produced by plants (Went, 1964(Went, , 1967, the generation of condensation aerosols by homogeneous gas reactions (Walter, 1973), the formation of condensation nuclei by evaporation processes in semiarid terrains (Twomey, 1960); and the production of organic particulate ma terial by the decay, biodegradation, and weathering of plant material.…”

Section: Sources Of Atmospheric Particulates and Aerosolsmentioning

confidence: 99%

Proceedings of the first annual William Pecora Memorial Symposium, October 1975, Sioux Falls, South Dakota

Woll¹,

Fischer²

1977

Professional Paper

View full text Add to dashboard Cite

show abstract

“…The complexity of blown sand movement has led researchers to divide the process into four interacting sub-processes: jumping of the sand grains [1][2][3][4][5][6][7][8][9], their movement in the air flow [10][11][12][13][14], changes of the air flow due to the presence of moving sand grains [15,16], and impacts between falling sand grains and sand grains in the underlying sand bed [17][18][19][20][21]. In addition, several scientists have studied key parameters of aeolian sand movement.…”

mentioning

confidence: 99%

Redevelopment of liftoff rates of saltating sand grains based on a simple optimization model

Cao

Zou

2010

Sci. China Earth Sci.

View full text Add to dashboard Cite

This paper is a redevelopment result of liftoff rates of saltating sand grains based on our previous work. Aeolian sand flow is a complex multi-phase flow because of a special two-phase gas-solid flow near ground surface. Despite extensive research on the movement of blowing sand, no model fully characterizes aeolian sand flow, and large differences often exist between simulations of aeolian sand movement and field observations. One key problem is a few of sufficient research on liftoff rates of saltating sand grains (also called the number of liftoff sand grains per unit time and per unit bed area). It is necessary to research in advance liftoff rates of saltating sand grains. We redeveloped liftoff rates of saltating sand grains by establishing an optimization model based on the flux of aeolian sand flow at different heights of the sampler in wind tunnel and the simulated capture of saltating sand grains by different heights of the sampler that are from different liftoff position (distance from the sampler) in order to revise previous inversion condition of liftoff rates of saltating sand grains. Liftoff rates increased rapidly with increasing wind speed. For frictional wind velocities of u * = 0.67, 0.77, 0.82, 0.83, and 0.87 m s −1 , liftoff rates were 3840, 954502, 5235114, 5499407, and 7696291 sand grain s −1 m −2 , respectively. These rates could be expressed as the square of the instantaneous frictional wind velocity and a constant (0.663) that differs from the critical (threshold) frictional wind velocity at which saltation begins. Although our results require additional experimental validation and the simple optimization model must be improved, they nonetheless provide a strong basis for future research.liftoff rates of saltating sand grains, optimization model, wind tunnel, two-phase gas-solid flow Citation:Chen H, Zou X Y. Redevelopment of liftoff rates of saltating sand grains based on a simple optimization model.

show abstract

On the Wind Erosion of Small Particles 1

Cited by 7 publications

References 4 publications

Measurement of sand creep on a flat sand bed using a high‐speed digital camera: Mesoscopic features of creeping grains

Measurement of sand creep on a flat sand bed using a high‐speed digital camera: Mesoscopic features of creeping grains

Proceedings of the first annual William Pecora Memorial Symposium, October 1975, Sioux Falls, South Dakota

Redevelopment of liftoff rates of saltating sand grains based on a simple optimization model

Contact Info

Product

Resources

About