Aerodynamic Entrainment Research Articles

Estimation of aerodynamic entrainment in developing wind-blown sand flow.

Understanding aerodynamic entrainment, a critical process in wind-blown sand dynamics, remains challenging due to the difficulty of isolating it from other mechanisms, such as impact entrainment. Aerodynamic entrainment initiates the movement of surface particles, influencing large-scale processes like sediment transport and dune formation. Previous studies focused on average aerodynamic shear stress to estimate entrainment, but the role of impulse events, which cause significant shear stress fluctuations, remains under-explored. We used 12 hot-film shear sensors to measure the spatiotemporal distribution of aerodynamic shear stress during wind-blown sand flow development. We identified impulse events exceeding the entrainment threshold and analyzed their intensity, classifying particle movement as rocking, rolling, or saltation. Results indicate that after a 2-m fetch, sediment mass flux stabilizes, with aerodynamic shear stress decreasing to 78% of the entrainment threshold. We identified key trends, including the stabilization of rocking events beyond x = 4.5 m and a significant decrease in saltation frequency, indicating fully developed wind-blown sand flow. Impulse characteristics stabilize at a greater distance (4.5 m) than sediment transport (2 m) because turbulent airflow evolves more slowly. Our findings show that impulse events significantly influence aerodynamic entrainment. These insights enhance understanding of sediment transport dynamics and improve modeling of sand dune movement.

Characteristics of dust emission over desert steppe

Desert steppe is widely distributed in wind erosion regions, and is also an important potential dust emission source in the regions. Recognition of dust emission characteristics of desert steppe is the foundation for accurate simulation of dust emission in wind erosion regions; however, few related studies have been conducted in desert steppe areas. In this study, we selected four sites in a region of desert steppe to conducting dust emission observations, analyzing the characteristics of horizontal saltation flux and vertical dust flux, identifying the suitable models for desert steppe, and examining the relationship between saltation bombardment efficiency and wind friction speed (u*). The results revealed the following: the supply of saltation particles in most desert steppe is unlimited, the intensity of saltation is reasonably high, and the modified Owen-type model is suitable for predicting sediment transport above desert steppe. Dust emission intensity in desert steppe is lower than that in other land use types under similar wind speeds. Schemes based on saltation bombardment theory (i.e., the MB95, Shao93, and Kok12 schemes) were found suitable for predicting vertical dust flux above desert steppe, the Kok12 dust emission scheme performed slightly better than the other two schemes. Saltation bombardment is the main mechanism for dust emission when u*s exceeds a threshold u*s (u*ts), but aerodynamic entrainment also plays an important role in dust emission, especially when u*s < u*ts. The saltation bombardment efficiency of desert steppe is less than that of other land use types. The trend of change in saltation bombardment efficiency with wind speed varies at different sites. Soil properties affect the dependence of saltation bombardment efficiency on u*. Desert steppe is an important dust emission source in certain regions, and improved understanding of dust emission in desert steppe areas is required.

Probing Iceland's dust-emitting sediments: particle size distribution, mineralogy, cohesion, Fe mode of occurrence, and reflectance spectra signatures

Abstract. Characterising the physico-chemical properties of dust-emitting sediments in arid regions is fundamental to understanding the effects of dust on climate and ecosystems. However, knowledge regarding high-latitude dust (HLD) remains limited. This study focuses on analysing the particle size distribution (PSD), mineralogy, cohesion, iron (Fe) mode of occurrence, and visible–near infrared (VNIR) reflectance spectra of dust-emitting sediments from dust hotspots in Iceland (HLD region). Extensive analysis was conducted on samples of top sediments, sediments, and aeolian ripples collected from seven dust sources, with particular emphasis on the Jökulsá basin, encompassing the desert of Dyngjunsandur. Both fully and minimally dispersed PSDs and their respective mass median particle diameters revealed remarkable similarities (56 ± 69 and 55 ± 62 µm, respectively). Mineralogical analyses indicated the prevalence of amorphous phases (68 ± 26 %), feldspars (17 ± 13 %), and pyroxenes (9.3 ± 7.2 %), consistent with thorough analyses of VNIR reflectance spectra. The Fe content reached 9.5 ± 0.40 wt %, predominantly within silicate structures (80 ± 6.3 %), complemented by magnetite (16 ± 5.5 %), hematite/goethite (4.5 ± 2.7 %), and readily exchangeable Fe ions or Fe nano-oxides (1.6 ± 0.63 %). Icelandic top sediments exhibited coarser PSDs compared to the high dust-emitting crusts from mid-latitude arid regions, distinctive mineralogy, and a 3-fold bulk Fe content, with a significant presence of magnetite. The congruence between fully and minimally dispersed PSDs underscores reduced particle aggregation and cohesion of Icelandic top sediments, suggesting that aerodynamic entrainment of dust could also play a role upon emission in this region, alongside saltation bombardment. The extensive analysis in Dyngjusandur enabled the development of a conceptual model to encapsulate Iceland's rapidly evolving high dust-emitting environments.

Understanding snow saltation parameterizations: lessons from theory, experiments and numerical simulations

Abstract. Drifting and blowing snow are important features in polar and high mountain regions. They control the surface mass balance in windy conditions and influence sublimation of snow and ice surfaces. Despite their importance, model representations in weather and climate assessments have high uncertainties because the associated physical processes are complex and highly variable in space and time. This contribution investigates the saltation system, which is the lower boundary condition for drifting and blowing snow models. Using a combination of (previous) measurements and new physics-based modeling with large-eddy simulation (LES), we show that the prevailing parameterizations that describe the saltation system in atmospheric models are based on contradictory assumptions: while some scaling laws are typical of a saltation system dominated by aerodynamic entrainment, others represent a saltation system controlled by splash. We show that both regimes can exist, depending on the friction velocity. Contrary to sand saltation, aerodynamic entrainment of surface particles is not negligible. It is important at low wind speeds, leading to a saltation height and near-surface particle velocity which increase with the friction velocity. In a splash-dominated saltation regime at higher friction velocities, the saltation height and near-surface particle velocity become invariant with the friction velocity and closer to what is observed with sand. These findings are accompanied by a detailed description of the theoretical, experimental and numerical arguments behind snow saltation parameterizations. This work offers a comprehensive understanding of the snow saltation system and its scaling laws, useful for both modelers and experimentalists.

Effect of plant shapes on sand transport rate and aerodynamic particle entrainment rate from the perspective of plant drag

Plant shape is an important factor affecting sand transport rate and aerodynamic particle entrainment rate. Two different types of flexible plant models (one is slender and the other has a large upper part and a small lower part) and a rigid tree-like plant model are selected with approximately zero basal-to-frontal area ratio. The sand transport rate, aerodynamic entrainment rate and shear stress partitioning on vegetated surfaces were measured under different plant densities and incoming wind speeds in a wind tunnel. The results show that the sand transport rate and aerodynamic entrainment rate on vegetated surfaces decrease with an increase in lateral cover and form drag of plant models. The relationship between sand transport rate, aerodynamic entrainment rate and drag parameter β (defined as the drag coefficient ratio of a plant model to the bare surface) is established by introducing the attenuation function of effective wind speed, which decays exponentially with an increase in lateral cover and linearly with an increase in drag coefficient ratio β. The present findings contribute to our understanding of how different vegetation types affect sediment transport rate and aerodynamic entrainment rate.

Wind tunnel simulation of wind erosion and dust emission processes, and the influences of soil texture

Dust emission caused by wind erosion of soil is an important surface process in arid and semi-arid regions. However, existing dust emission models pay insufficient attention to the impacts of aerodynamic entrainment of particles. In addition, studies of wind erosion processes do not adequately account for the dynamics of wind erosion rates and dust emission fluxes, or for the impact of soil texture on dust emission. Our wind tunnel simulations of wind erosion and dust emission showed that the soil texture, wind erosion duration, and shear velocity are major factors that affect the dynamics of wind erosion and dust emission. Because of the limited supply of surface sand and the change in surface erosion resistance caused by surface coarsening during erosion, the wind erosion rate and the flux of particles smaller than 10 μm (PM10) caused by aerodynamic entrainment decreased rapidly with increasing erosion duration, which suggests that surface wind erosion and dust emission occur primarily during the initial stage of wind erosion. The PM10 emission efficiency decreased with increasing shear velocity following a power function, and finer textured sandy loam soils had greater PM10 emission efficiency than loamy sand soils.

Hysteresis and Surface Shear Stresses During Snow-Particle Aeolian Transportation

Surface shear stresses produced by wind and particle collision play a key role in aerodynamic entrainment and splash processes. The fluid shear stress at the surface during aeolian transport has been researched for decades; however, the equilibrium property reported in the literature, numerical simulations, and experiments is inconsistent. To discuss this discrepancy, this study investigates fluid and particle shear stresses at the surface during the aeolian transport of snow particles using a two-dimensional random-flight model of drifting snow. The simulations are performed for various friction velocities on a loose snow bed. By varying the wind conditions in stages, the transport hysteresis is confirmed, and the impact threshold is estimated from the particle transport rate (0.206,hbox {m,s}^{-1}). The friction velocity at the surface during transport decreases marginally with an increase in wind speed caused by the impact threshold, revealing that our results do not contradict Owen’s second hypothesis. The total shear stress, which is calculated by summing the fluid and particle shear stresses, is vertically uniform in the equilibrium state; thus, the increase in the particle shear stress decreases the fluid shear stress at the surface. The equilibrium property of the fluid shear stress near the surface changes significantly with height (from a decreasing trend to an increasing trend) because the particle shear stress decreases rapidly in the height range of 1–10 mm. Our findings suggest that it is difficult to accurately measure the fluid shear stress in the surface vicinity using anemometers, and a new methodology is needed.

Simulation of aerodynamic entrainment with interparticle cohesions based on discrete element method

AbstractAerodynamic entrainment acts as the pioneer of saltation movement and is critical for understanding the development of aeolian phenomena. In this study, air‐driven particles whose bottoms have left the bed surface were considered to be entrainment particles; this definition differs from the previous definition considering the initiation of rolling. We simulated the aerodynamic lifting of surface particles on a randomly oriented sedimentary bed using the discrete element method (DEM); we also proved that particles do not leave the bed vertically with speeds equal to the speed required to reach the height of one grain diameter, as is widely accepted. Rather, the particles were found to leave the bed at a much smaller angle and with much larger velocities with respect to the bed surface. The rate of entrainment exhibits an approximately linear dependence on the shear velocity, not a quadratic dependence, because the velocity of the entrained particles increases linearly with shear velocity. Moreover, the interparticle cohesion, which was found to increase the fluid entrainment threshold significantly, had no effect on the entrainment rate or on the take‐off velocity and angular distributions of the entrained particles. This is because the collisions between the entrained and bed particles destroy the interparticle bonds. Herein, we summarize a complete entrainment scheme based on DEM simulations, which provides a new approach for exploring the development and evolution of aeolian transportation processes.

Towards a regional dust modeling system in the central Middle East: Evaluation, uncertainties and recommendations

This study aims towards an accurate regional dust modeling system in the central Middle East area (CME), through the implementation of the state-of-art dust parameterizations. The modeling system consists of the natural emission model NEMO, the meteorological model WRF and the chemistry transport model CAMx. An extensive evaluation of 16 different configurations has been realized, incorporating all the combinations of the components utilized in the state-of-art dust modeling approaches, namely the drag partition, the sandblasting efficiency, the horizontal mass flux, as well two commonly used soil particle size distributions. Daily mean PM10 measurements in Doha, as well the satellite AOD products of MODIS have been used for the quantitative and the qualitative assessment of the simulations. Noteworthy, each of these assessments did not yield to the exact same ranking of the configurations (e.g. best five) but they assisted on identifying clear patterns. For example, a consistent overestimation of the daily mean PM10, when the MacKinnon's drag partition scheme is utilized, was found. On the other hand, the assessments led to best three performing configurations, with common components the Raupach's drag partition scheme and Alfaro and Gomes sandblasting efficiency. Although their overall performance is good, several issues were found i.e. on individual dust events and a mean underestimation during the studied period, ranging from −49 to −75 μg/m3. One cause of this underestimation could be the aerodynamic entrainment, a mechanism usually neglected from the dust modeling approaches. Another cause could be missed regional and/or local sources or underestimation of their emission rates.

The Influence of Surface Stress Fluctuation on Saltation Sand Transport Around Threshold

AbstractMultiscale wind velocity fluctuation and complex inertial response of sand saltation to wind variations give rise to intermittent and nonuniform sand transport, which greatly challenges the prediction of transport rate under wind conditions around saltation threshold. In this paper, three‐dimensional sand saltation within simulation domain of wind tunnel scale is modeled based on large eddy simulation of turbulent wind. Special attention is paid to the prediction of surface shear stress and consequently aerodynamic entrainment. When the wall stress model considering the influence of large‐scale turbulent structures was employed in case of relatively small resistance level for calculating particle aerodynamic entrainment, the model results predict sand transport below the impact threshold. The sand transport rate in this regime increases exponentially with mean wall stress, in contrast to the standard power law‐like behavior above the impact threshold. Aerodynamic entrainment and strong transport events lag behind high‐speed fluids sweep on a large scale even in wind tunnel, but the spatiotemporal variability of small‐scale sand transport is still unclear and quite complex due to transport inertia.

A modal discontinuous Galerkin method for simulating dusty and granular gas flows in thermal non-equilibrium in the Eulerian framework

A modal discontinuous Galerkin method was developed for computing compressible rarefied gaseous flows interacting with rigid particles and granular medium. In contrast to previous particle-based models that were developed to handle rarefied flows or solid phase particles, the present computational method employs full continuum-based models. This work is one of the first attempts to apply the modal discontinuous Galerkin method to a two-fluid model framework, which covers a wide range of gas and solid phase regimes, from a continuum to non-equilibrium gas, and from dusty to collisional regimes. The rarefaction effects were taken into account by applying the second-order Boltzmann-Curtiss-based constitutive relationship in a two-fluid system of equations. For the dust phase, computational models were developed based on the kinetic theory of the granular flows. Due to the orthogonal property of the basis functions in the method, no specific treatment of the source terms, commonly necessary in the conventional finite volume method, was required. Moreover, a high-fidelity approach was selected to treat the non-strictly hyperbolic equations of a dusty gas. This allows the same inviscid numerical flux functions to be applied to both the gaseous Euler and solid pressureless-Euler system of equations. Further, we observed that, for the discretization of the viscous fluxes in multiphase cases, the local discontinuous Galerkin is superior to the first method by Bassi and Rebay. After a verification and validation study, the new computational model was used to simulate the impingement of an underexpanded jet on a dusty surface in a rarefied condition. A surface erosion model based on viscous erosion associated with aerodynamic entrainment was implemented at a solid surface. Simulation cases in the near-field of the nozzle flow were tested to evaluate the capabilities of the present computational model in handling the challenging problems of multi-scale multiphase flows.

A study on the initiation of saltation in the model of wind-blown sand transport considering the effect of turbulence

Turbulence plays an important role in the transport of wind-blown sand. If the model of wind-blown sand transport considering the effect of turbulence is to be established, the influence of turbulence needs to be introduced into the four sub-processes of saltation, namely (1) aerodynamic entrainment, (2) the subsequent trajectories of saltating particles, (3) the collision of particles with the soil surface and the subsequent splashing of surface particles into the fluid stream, and (4) the modification of the wind profile through momentum transfer between the wind flow and saltating particles. In this paper, turbulence is introduced into two models predicting the first and the third sub-processes of saltation by the aerodynamic drag force and the creep velocity of surface particles respectively. The effects of turbulence on the two sub-processes are discussed. Our results show that turbulence has an important effect on aerodynamic entrainment. That is, when the wind velocity exceeds the threshold velocity, about 20% of all surface particles are unable to lift-off from the bed surface. The effect of turbulence on aerodynamic entrainment is mainly caused by large-scale turbulent motions. The model of number of lifting sand particles caused by aerodynamic drag force is modified by introducing a lift-off rate $$\sigma$$ (i.e., the ratio of the number of actually lifting sand particles judged by our theory to the total number of lifting sand particles judged by existing theory), which is $$N_{a} = \sigma \times \zeta \rho \;(u_{\tau }^{2} - u_{c}^{2} )$$ , where σ is defined as the lift-off rate, uτ is the friction wind velocity, uc is the threshold velocity, ρ is the air density, and ζ is the empirical constant. In addition, the results show that the cumulative distribution of creep velocity under the direct action of turbulence (which can be characterized by the SGompertz distribution) has little effect on the velocity distributions of rebound particles and ejected particles.

Cohesion‐Induced Enhancement of Aeolian Saltation

AbstractThe wind‐driven saltation of granular material plays a key role in various geophysical processes on Earth, Mars, Venus, and Titan. Although interparticle cohesion is known to limit the number of grains lifted from the surface through aerodynamic entrainment and granular splash, the role of cohesion in the development of saltation from onset to steady state is still poorly understood. Using a numerical model based on the discrete element method, we show that saltation over cohesive beds sustains itself at wind speeds 1 order of magnitude smaller than those necessary to initiate it, giving rise to hysteresis in which the occurrence of transport depends on the history of the wind. Our results further suggest that saltation over cohesive beds requires much longer distances to saturate, thereby increasing the size of the smallest stable bed forms. These findings have implications for dune formation, dust emission, and snow sublimation over cohesive beds.

The effect of roughness density of gobi beds on the entrainment of sediment by wind: A wind tunnel study

Although gobi is a major source of dust storms in northern China, few studies have investigated the effect of roughness density (λ) of gobi beds on aeolian sediment entrainment. This wind tunnel study quantitatively evaluated the effect of λ on aeolian entrainment from gobi beds with λ of 0.05–0.51 using Rt and RQ. Rt referred to the ratio of the entrainment threshold for a bare sand bed to those of gobi beds; RQ was the entrainment rate ratio, whose calculation was just reversed with Rt. The results indicated that a two-to five-fold increase in entrainment threshold and 41.4–100% of entrainment rate was attenuated within an experimental friction velocity (u*) range of 0.40–0.63 m s−1. Moreover, the variation of RQ with λ was almost negligible, as λ reached 0.176, 0.203, 0.313, and 0.375 for u* values of 0.40, 0.49, 0.54, and 0.63 m s−1, respectively, which were specific for the Gobi Desert with their typical gravel beds. This study also indicated that for higher u* of 0.54 and 0.63 m s−1, aerodynamic entrainment plays a significant role in aeolian entrainment, whereas at lower u* of 0.40 and 0.49 m s−1, splash entrainment exerts a greater impact.

Development of a large-eddy simulation coupled with Lagrangian snow transport model

The aim of this study is to develop a large-eddy simulation (LES)-coupled Lagrangian snow transport model. This model consists of an LES for turbulent flow fields, and a particle transport simulation model based on Newton's equations of motion. Particles are treated as point masses for turbulent flow fields in this study. The interactions of momentum exchange between a fluid and particles are considered. The particle transport simulation includes three physical sub-processes on the snow surface: aerodynamic entrainment, rebound, and splash. Then, we simulated particle transport within a turbulent boundary layer under the low-wind condition in which saltation intermittently occurs. This simulation was calculated with high frequency and high resolution to capture the fine turbulent structures. The initial stage of saltation mainly related to sweeps, and particles were ejected through the process of aerodynamic entrainment. These ejected particle induced more saltating particles, and the number of saltating particles transported through the processes of splash and rebound increased and became dominant as time proceeds. In such processes of splash and rebound under low-wind conditions, the particle transport might be unaffected by turbulent structures.

Parameterization of dust flux emitted by convective turbulent dust emission (CTDE) over the Horqin Sandy Land area

A new convective turbulent dust emission (CTDE) empirical parameterization scheme was developed and validated using the observational data of dust concentrations and meteorological parameters over the Horqin Sandy Land area. Moreover, different CTDE schemes were compared and discussed. The statistical results from the observations in 2016 showed that the proportion of dust emission fluxes emitted by CTDE is 27% for all dust emission which indicates that the significance of CTDE events for the contribution of atmospheric dust aerosols. In addition, dust emission fluxes emitted by CTDE constituted up to 78% of the total dust emission fluxes due to direct aerodynamic entrainment, which verified that CTDE is indeed the most important and major form of aerodynamic entrainment dust emission. A new CTDE empirical parameterization scheme (Fmod=2.93×w∗1.5, where w∗ is the convective velocity scale), was established and validated based on nine typical CTDE events observed at the Horqin site in 2016, and the model predictions of the new CTDE scheme were in a good agreement with the observations both in magnitude and variation. The results of the model predictions using the MK14 scheme and Li scheme were also good, but their schemes exaggerated the impact of shear-driven turbulence, which caused discrepancies between the new empirical parameterization scheme and the MK14 scheme. Moreover, effects of soil moisture on CTDE were investigated in this study, and the results showed that there was no obvious relationship between soil moisture content and Fobs during CTDE events. This finding was likely because only dust particles in the upper few millimeters of the soil surface, where soil moisture content was relatively low in semi-arid region, can be emitted into the atmosphere during CTDE events due to weak wind speeds. In addition, compared with the saltation-bombardment and/or aggregation-disintegration dust emission (SADE) event, the process of a CTDE event may be aerodynamic lift limitation, not supply limitation.

Wind tunnel experiments on dust emissions from different landform types

The measurement and assessment of dust emissions from different landforms are important to understand the atmospheric loading of PM10 (particulate matter ≤10 μm aerodynamic diameter) and to assess natural sources of dust; however, the methodology and technique for determining the dust still present significant research challenges. In the past, specialized field observation and field wind tunnel studies have been used to understand the dust emission. A series of wind tunnel tests were carried out to identify natural sources of dust and measure the magnitudes of dust emissions from different landforms. The method used in this study allowed the measurement of the PM10 emission rate using a laboratory based environmental boundary layer wind tunnel. Results indicated that PM10 emissions demonstrated strong temporal variation and were primarily driven by aerodynamic entrainment. Sand dunes, playa, and alluvial fans had the largest dust emission rates (0.8–5.4 mg/(m2•s)) while sandy gravel, Gobi desert and abandoned lands had the lowest emission rates (0.003–0.126 mg/(m2•s)). Dust emissions were heavily dependent on the surface conditions, especially the availability of loose surface dust. High dust emissions were a result of the availability of dustparticle materials for entrainment while low dust emissions were a result of surface crusts and gravel cover. Soil surface property (surface crusts and gravel cover) plays an important role in controlling the availability of dust-sized particles for entrainment. The dust emission rate depended not only on the surface conditions but also on the friction velocity. The emission rate of PM10 varies as a power function of the friction velocity. Although dynamic abrasion processes have a strong influence on the amount of dust entrainment, aerodynamic entrainment may provide an important mechanism for dust emissions. Large volumes of dust entrained by aerodynamic entrainment cannot only occur at low shear velocity without saltation, but may dominate the entrainment process in many arid and semi-arid environments. So it may also be responsible for large magnitude dust storms. Playa and alluvial fan landforms, prior to developing a surface crust, may be the main sources of dust storms in Qinghai Province.

Wind tunnel observations of weak and strong snow saltation dynamics

AbstractTheoretical considerations suggest that saltation dynamics is dominated by either aerodynamic entrainment or by a combination of ejection and rebound at a given time and location. Calling these two regimes “weak” and “strong” saltation, respectively, we have investigated high‐resolution snow mass flux measurements by shadowgraphy in a cold wind tunnel to determine whether these two regimes can be experimentally reproduced. In this contribution, we first suggest that aerodynamic entrainment should lead to a negative correlation in the growth rates of horizontal versus vertical mass fluxes, while for the ejection regime, a positive correlation is plausible. Based on this criterion, we find evidence of weak and strong saltation in our data. Weak saltation is characterized by smaller peaks of horizontal mass flux; however, these peaks have a higher growth rate and therefore are typically narrow. The larger peaks are associated with strong saltation, are wider, and their frequency of occurrence increases with increasing overall saltation mass flux.

Surface renewal as a significant mechanism for dust emission

Abstract. Wind tunnel experiments of dust emissions from different soil surfaces are carried out to better understand dust emission mechanisms. The effects of surface renewal on aerodynamic entrainment and saltation bombardment are analyzed in detail. It is found that flow conditions, surface particle motions (saltation and creep), soil dust content and ground obstacles all strongly affect dust emission, causing its rate to vary over orders of magnitude. Aerodynamic entrainment is highly effective, if dust supply is unlimited, as in the first 2–3 min of our wind tunnel runs. While aerodynamic entrainment is suppressed by dust supply limits, surface renewal through the motion of surface particles appears to be an effective pathway to remove the supply limit. Surface renewal is also found to be important to the efficiency of saltation bombardment. We demonstrate that surface renewal is a significant mechanism affecting dust emission and recommend that this mechanism be included in future dust models.

The formation of snow streamers in the turbulent atmosphere boundary layer

Abstract The drifting snow in the turbulent atmosphere boundary layer is an important type of aeolian multi-phase flow. Current theoretical and numerical studies of drifting snow mostly consider the flow field as steady wind velocity. Whereas, little is known about the effects of turbulent wind structures on saltating snow particles. In this paper, a 3-D drifting snow model based on Large Eddy Simulation is established, in which the trajectory of every snow grain is calculated and the coupling effect between wind field and snow particles is considered. The results indicate that the saltating snow particles are re-organized by the suction effect of high-speed rotating vortexes, which results in the local convergence of particle concentration, known as snow streamers. The turbulent wind leads to the spatial non-uniform of snow particles lifted by aerodynamic entrainment, but this does not affect the formation of snow streamers. Whereas the stochastic grain-bed interactions make a great contribution to the final shapes of snow streamers. Generally, snow streamers display a characteristic length about 0.5 m and a characteristic width of approximately 0.16 m, and their characteristic sizes are not sensitive to the wind speed. Compared to the typical sand streamer, snow streamer is slightly narrower and the occurrence of other complex streamer patterns is later than that of sand streamers due to the better follow performance of snow grains with air flow.