Snow particle speeds in drifting snow

AbstarctIn Antarctica, blowing snow accounts for a major component of the surface mass balance near the coast. Measurements of precipitation and blowing snow are scarce, and therefore collected data would allow testing of numerical models of mass flux over this region. A present weather station (PWS), Biral VPF730, was set up on the coast at Cap Prud’homme station, 5 km from Dumont d’Urville (DDU), principally to quantify precipitation. Since we expected to be able to determine blowing-snow fluxes from the PWS data, we tested this device first on our experimental site, the Lac Blanc pass. An empirical calibration was made with a snow particle counter. Although the physics of the phenomenon was not well captured, the flux outputs were better than those from FlowCapts. The first data from Antarctica were reanalyzed. The new calibration seems to be accurate for estimating the high blowing-snow flux with an interrogation of the precipitation effects.

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Characteristics of Drifting Snow at Mizuho Station, Antarctica

Annals of Glaciology ◽

10.3189/1985aog6-1-71-75 ◽

1985 ◽

Vol 6 ◽

pp. 71-75 ◽

Cited By ~ 4

Author(s):

Sbuhei Takahashi

Keyword(s):

Temperature Dependence ◽

Sea Level ◽

Wind Velocity ◽

Particle Shape ◽

East Antarctica ◽

Fall Velocity ◽

Drift Flux ◽

Drifting Snow ◽

Snow Drift ◽

Snow Particle

Observations of drifting snow were carried out at Mizuho Station (70°42'S, 44°20'E, 2230 m above sea level), East Antarctica, in 1982. Drift flux was proportional to about the 8th power of wind velocity above 1 m and about the 4th power below 0.1 m, while snow drift transport rate was proportional to about the 5th power. For drift flux at 1 m height, the power had a temperature dependence, decreasing above -20 °C. Visibility was proportional to about the -8th power of wind velocity; this is explained by the power relation between drift flux and wind velocity. The repose angle of drifting snow particles was observed by the inclination of a cone-shaped deposit on a disk; it was more than 80° when snow was falling and less than 80° without precipitation. The fall velocity of drifting snow particles, obtained by time-marked trajectories of particles, was between 0.3 and 0.9 m/s, and depended on wind velocity and snow particle shape.

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Mass-flux measurements in a cold wind tunnel: comparison of the mechanical traps with a snow-particle counter

Annals of Glaciology ◽

10.3189/172756401781819102 ◽

2001 ◽

Vol 32 ◽

pp. 121-124 ◽

Cited By ~ 3

Author(s):

D. Font ◽

T. Sato ◽

K. Kosugi ◽

A. Sato ◽

J. M. Vilaplana

Keyword(s):

Wind Tunnel ◽

Mass Flux ◽

Field Experiments ◽

Particle Counter ◽

Drifting Snow ◽

Flux Measurements ◽

Snow Particle ◽

Cold Wind ◽

Good Agreement ◽

Snow And Ice

AbstractDuring September and October 1997, in the framework of a stay at the Shinjo Branch of Snow and Ice Studies, we used a Cryospheric Environment Simulator (Higashiura and others, 1997) and simulated drifting snow to test four mechanical traps. First we present the intercomparison of the four mechanical gauges, then we compare the gauges with the snow-particle counter (SPG). Comparing the four different traps tested, we have observed that the box type (snow collector) is generally more efficient than the net-type collectors. These results confirm the tendency observed in field experiments (Font and others, 1998b). Using the SPG to calibrate the mechanical gauges, we observed that the net-type traps underestimate transport in low-transport conditions, but as transport increases the underestimation tends to zero. Comparing the snow collector with the SPG, we observed good agreement between the two gauges.

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Evaluation of the FlowCapt Acoustic Sensor for the Aeolian Transport of Snow

Journal of Atmospheric and Oceanic Technology ◽

10.1175/jtech-d-14-00104.1 ◽

2015 ◽

Vol 32 (9) ◽

pp. 1630-1641 ◽

Cited By ~ 15

Author(s):

Alexandre Trouvilliez ◽

Florence Naaim-Bouvet ◽

Hervé Bellot ◽

Christophe Genthon ◽

Hubert Gallée

Keyword(s):

Second Generation ◽

Winter Season ◽

Bench Test ◽

Aeolian Transport ◽

Particle Counter ◽

Drifting Snow ◽

Mass Fluxes ◽

Snow Particle ◽

Set Up ◽

Snow Mass

AbstractFlowCapt acoustic sensors, designed for measuring the aeolian transport of snow fluxes, are compared to the snow particle counter S7optical sensor, considered herein as the reference. They were compared in the French Alps at the Lac Blanc Pass, where a bench test for the aeolian transport of snow was set up. The two existing generations of FlowCapt are compared. Both seem to be good detectors for the aeolian transport of snow, especially for transport events with a flux above 1 g m−2 s−1. The second-generation FlowCapt is also compared in terms of quantification. The aeolian snow mass fluxes and snow quantity transported recorded by the second-generation FlowCapt are close to the integrative snow particle counter S7 fluxes for an event without precipitation, but they are underestimated when an event with precipitation is considered. When the winter season is considered, for integrative snow particle counter S7 fluxes above 20 g m−2 s−1, the second-generation FlowCapt fluxes are underestimated, regardless of precipitation. In conclusion, both generations of FlowCapt can be used as a drifting snow detector and the second generation can record an underestimation of the quantity of snow transported at one location: over the winter season, the quantity of snow transported recorded by the SPC is between 4 and 6 times greater than the quantity recorded by the second-generation FlowCapt.

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Wind and drifting-snow gust factor in an Alpine context

Annals of Glaciology ◽

10.3189/172756411797252112 ◽

2011 ◽

Vol 52 (58) ◽

pp. 223-230 ◽

Cited By ~ 14

Author(s):

Florence Naaim-Bouvet ◽

Mohamed Naaim ◽

Hervé Bellot ◽

Kouichi Nishimura

Keyword(s):

Wind Tunnels ◽

Wind Gust ◽

Gust Factor ◽

Wind Gusts ◽

Drifting Snow ◽

Order Of Magnitude ◽

Snow Particle ◽

Definition Of ◽

S Peak ◽

Gust Factors

AbstarctWind-transported snow is a common phenomenon in cold windy areas, creating snowdrifts and contributing significantly to the loading of avalanche release areas. It is therefore necessary to take into account snowdrift formation both in terms of predicting and controlling drift patterns. Particularly in an Alpine context, drifting snow is a nonstationary phenomenon, which has not been taken into account in physical modeling carried out in wind tunnels or in numerical simulations. Only a few studies have been conducted to address the relation between wind gusts and drifting-snow gusts. Consequently, the present study was conducted at the Lac Blanc pass (2700ma.s.l.) experimental site in the French Alps using a snow particle counter and a cup anemometer in order to investigate drifting-snow gusts. First, it was shown that the behavior of the wind gust factor was coherent with previous studies. Then the definition of wind gust factor was extended to a drifting-snow gust factor. Sporadic drifting-snow events were removed from the analysis to avoid artificially high drifting-snow gust factors. Two trends were identified: (1) A high 1 s peak and a mean 10 min drifting-snow gust factor, greater than expected, were observed for events that exhibited a gamma distribution on the particle width histogram. The values of drifting-snow gust factors decreased with increasing gust duration. (2) Small drifting-snow gusts (i.e. smaller than or of the same order of magnitude as wind gusts) were also observed. However, in this case, they were systematically characterized by a snow particle size distribution that differed from the two-parameter gamma probability density function.

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Characteristics of Drifting Snow at Mizuho Station, Antarctica

Annals of Glaciology ◽

10.1017/s0260305500010028 ◽

1985 ◽

Vol 6 ◽

pp. 71-75 ◽

Cited By ~ 17

Author(s):

Sbuhei Takahashi

Keyword(s):

Temperature Dependence ◽

Sea Level ◽

Wind Velocity ◽

Particle Shape ◽

East Antarctica ◽

Fall Velocity ◽

Drift Flux ◽

Drifting Snow ◽

Snow Drift ◽

Snow Particle

Observations of drifting snow were carried out at Mizuho Station (70°42'S, 44°20'E, 2230 m above sea level), East Antarctica, in 1982. Drift flux was proportional to about the 8th power of wind velocity above 1mand about the 4th power below 0.1 m, while snow drift transport rate was proportional to about the 5th power. For drift flux at 1 m height, the power had a temperature dependence, decreasing above -20 °C. Visibility was proportional to about the -8th power of wind velocity; this is explained by the power relation between drift flux and wind velocity. The repose angle of drifting snow particles was observed by the inclination of a cone-shaped deposit on a disk; it was more than 80° when snow was falling and less than 80° without precipitation. The fall velocity of drifting snow particles, obtained by time-marked trajectories of particles, was between 0.3 and 0.9 m/s, and depended on wind velocity and snow particle shape.

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Blowing and drifting snow in Alpine terrain: numerical simulation and related field measurements

Annals of Glaciology ◽

10.3189/1998aog26-1-174-178 ◽

1998 ◽

Vol 26 ◽

pp. 174-178 ◽

Cited By ~ 5

Author(s):

Peter Gauer

Keyword(s):

Numerical Simulation ◽

Numerical Model ◽

Three Dimensional ◽

Field Measurements ◽

Blowing Snow ◽

Related Field ◽

Drifting Snow ◽

Physically Based ◽

Snow Transport

A physically based numerical model of drifting and blowing snow in three-dimensional terrain is developed. The model includes snow transport by saltation and suspension. As an example, a numerical simulation for an Alpine ridge is presented and compared with field measurements.

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