The interaction between drifting snow and atmospheric turbulence

This paper presents a modelling study of the influence of suspended snow on turbulence in the atmospheric surface layer. Turbulence is diminished in drifting and blowing snow, since part of the turbulent energy is used to keep the particles in suspension. This decrease in turbulence directly affects the vertical turbulent fluxes of momentum and snow particles (and other scalars), and can effectively be simulated by introducing an appropriate Richardson number to account for the stability effects of the stably stratified air-snow mixture. We use a one-dimensional model of the atmospheric surface layer in which the Reynolds stress and turbulent suspended snow flux are parameterized in terms of their mean vertical gradients (first-order closure). The model calculates steady-state vertical profiles of mean wind speed, suspended snow mass in 16 size classes and stability parameters. Using the model, the influence of snowdrifting on the wind-speed profile is quantified for various values of the initial friction Velocity (which determines the steepness of the initial wind-speed profile). It will be demonstrated why the roughness length appears to increase when snowdrifting occurs. Finally, we present a parameterization of the effects of snowdrifting on atmospheric stability which can be used in data analyses as a first-order approximation.

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A simple recipe for estimating atmospheric stability solely based on surface-layer wind speed profile

Wind Energy ◽

10.1002/we.2203 ◽

2018 ◽

Vol 21 (10) ◽

pp. 937-941 ◽

Cited By ~ 5

Author(s):

Sukanta Basu

Keyword(s):

Surface Layer ◽

Wind Speed ◽

Atmospheric Stability ◽

Speed Profile ◽

Wind Speed Profile

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Effects of turbulent dispersion on the wind speed profile in the surface layer

Advances in Atmospheric Sciences ◽

10.1007/s00376-002-0045-5 ◽

2002 ◽

Vol 19 (5) ◽

pp. 794-806 ◽

Cited By ~ 1

Author(s):

Liu Shikuo ◽

Peng Weihong ◽

Huang Feng ◽

Chi Dongyan

Keyword(s):

Surface Layer ◽

Wind Speed ◽

Turbulent Dispersion ◽

Speed Profile ◽

Wind Speed Profile

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Length Scales of the Neutral Wind Profile over Homogeneous Terrain

Journal of Applied Meteorology and Climatology ◽

10.1175/2009jamc2148.1 ◽

2010 ◽

Vol 49 (4) ◽

pp. 792-806 ◽

Cited By ~ 38

Author(s):

Alfredo Peña ◽

Sven-Erik Gryning ◽

Jakob Mann ◽

Charlotte B. Hasager

Keyword(s):

Boundary Layer ◽

Surface Layer ◽

Wind Speed ◽

Wind Profile ◽

Mixing Length ◽

Speed Profile ◽

Wind Speed Profile ◽

Length Scales ◽

Spectral Models ◽

Good Agreement

Abstract The wind speed profile for the neutral boundary layer is derived for a number of mixing-length parameterizations, which account for the height of the boundary layer. The wind speed profiles show good agreement with the reanalysis of the Leipzig wind profile (950 m high) and with combined cup–sonic anemometer and lidar measurements (300 m high) performed over flat and homogeneous terrain at Høvsøre, Denmark. In the surface layer, the mixing-length parameterizations agree well with the traditional surface-layer theory, but the wind speed profile is underestimated when the surface-layer scaling is extended to the entire boundary layer, demonstrating the importance of the boundary layer height as a scaling parameter. The turbulence measurements, performed up to 160-m height only at the Høvsøre site, provide the opportunity to derive the spectral-length scales from two spectral models. Good agreement is found between the behaviors of the mixing- and spectral-length scales.

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Effects of Atmospheric Surface Layer Stability on Turbulent Fluxes of Heat and Water Vapor across the Water–Atmosphere Interface

Journal of Hydrometeorology ◽

10.1175/jhm-d-16-0042.1 ◽

2016 ◽

Vol 17 (11) ◽

pp. 2835-2851 ◽

Cited By ~ 9

Author(s):

Yusri Yusup ◽

Heping Liu

Keyword(s):

Heat Flux ◽

Surface Layer ◽

Wind Speed ◽

Temperature Gradient ◽

Atmospheric Surface Layer ◽

Numerical Models ◽

Atmospheric Stability ◽

Stable Conditions ◽

Vapor Pressure Gradient ◽

Stability Ranges

Abstract Widely used numerical models to estimate turbulent exchange of latent heat flux (LE) and sensible heat flux H across the water–atmosphere interface are based on the bulk transfer relations linked indirectly to atmospheric stability, even though the accurate prediction of the influence of stability on fluxes is uncertain. Here eddy covariance data collected over the water surface of Ross Barnett Reservoir, Mississippi, was analyzed to study how atmospheric stability and other variables (wind speed, vapor pressure gradient, and temperature gradient) in the atmospheric surface layer (ASL) modulated LE and H variations in different stability ranges. LE and H showed right-skewed, bell-shaped distributions as the ASL stability shifted from very unstable to near neutral and then stable conditions. The results demonstrate that the maximum (minimum) LE and H did not necessarily occur under the most unstable (stable) conditions, but rather in the intermediate stability ranges. No individual variables were able to explain the dependence of LE and H variations on stability. The coupling effects of stability, wind speed, and vapor pressure gradient (temperature gradient) on LE (H) primarily caused the observed variations in LE and H in different stability ranges. These results have important implications for improving parameterization schemes to estimate fluxes over water surfaces in numerical models.

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An empirical-analytical model of the vertical wind speed profile above and within an Amazon forest site

Meteorological Applications ◽

10.1002/met.1543 ◽

2015 ◽

Vol 23 (1) ◽

pp. 158-164 ◽

Cited By ~ 3

Author(s):

Cledenilson Mendonça de Souza ◽

Cléo Quaresma Dias-Júnior ◽

Júlio Tóta ◽

Leonardo Deane de Abreu Sá

Keyword(s):

Wind Speed ◽

Analytical Model ◽

Vertical Wind ◽

Forest Site ◽

Amazon Forest ◽

Speed Profile ◽

Wind Speed Profile ◽

Vertical Wind Speed

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Field test of a new snow-particle counter (SPC) system

Annals of Glaciology ◽

10.3189/s0260305500011411 ◽

1993 ◽

Vol 18 ◽

pp. 149-154 ◽

Cited By ~ 18

Author(s):

Takeshi Sato ◽

Tadashi Kimura ◽

Taminoe Ishimaru ◽

Toshisuke Maruyama

Keyword(s):

Wind Speed ◽

Mass Flux ◽

Particle Trajectory ◽

Particle Diameter ◽

Blowing Snow ◽

Fraunhofer Diffraction ◽

Wind Speed Profile ◽

Particle Counter ◽

Sampling Volume ◽

Snow Particle

The optical system of the snow-particle counter (SPC), which was developed by Schmidt in 1977, has been improved. A laser diode is used as a light source, achieving uniform sensitivity to a blowing snow particle regardless of the location of particle trajectory within a sampling volume. The light entering a slit, which may be affected by a blowing snow particle, is perfectly detected by use of a piano-cylindrical lens and a dual-type photodiode. A signal processor has been developed to get output voltage proportional to the mass flux of blowing snow.From the estimates based on blowing snow characteristics and wind speed profile, the new SPC system can accurately detect all the particles of effective sizes at least at a height above 0.1 m when the wind speed at a height of 1 m is less than 15 m s−1.Considering the Fraunhofer diffraction by both the wire and the particle, the relation between a particle diameter and sensor output of the new SPC system is derived from the calibration with spinning wires.Mass flux obtained with the new SPC system was found to be close to that with a snow trap. The system was operated continuously for at least nine days using two 35 A h lead batteries.

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