Related Experiment Video
Updated: Aug 13, 2026
06:27
Simulating Impacts of Ice Storms on Forest Ecosystems
Published on: June 30, 2020
Blast noise propagation above a snow cover
1US Army Cold Regions Research and Engineering Laboratory, Hanover, New Hampshire 03755, USA. dalbert@crrel.usace.army.mil
The Journal of the Acoustical Society of America
|June 27, 2001
Summary
A porous medium model accurately simulates acoustic wave propagation through dry snow, improving upon viscoelastic models. This research enhances understanding of acoustic signals in snowpack for better geophysical analysis.
Area of Science:
- Geophysics
- Acoustics
- Snow Science
Background:
- Acoustic waveform propagation through snow covers is crucial for geophysical studies.
- Previous models often used viscoelastic treatments, which may not fully capture snowpack complexities.
Purpose of the Study:
- To investigate the effectiveness of a porous medium model for simulating acoustic wave propagation over dry snow.
- To compare the porous medium model's predictions with a viscoelastic model and experimental data.
Main Methods:
- Simulated horizontally traveling acoustic waveforms using a rigid-ice-frame porous medium model.
- Analyzed waveforms from 1-kg explosions over dry snow (11-20 cm thick) at distances of 100-1400 m.
- Compared model predictions with measured data and a viscoelastic solid model.
Main Results:
- The rigid-porous model showed significantly better agreement with measured waveforms than the viscoelastic model.
- Predicted average snow depth (18 cm) and flow resistivities (16-31 kPa s m⁻²) aligned with observations.
- Upwind propagation reduced pulse broadening but increased amplitude decay due to refraction.
Conclusions:
- A porous medium model is superior to viscoelastic models for simulating acoustic propagation in dry snow.
- The model provides reliable estimates of snow depth and flow resistivity.
- Understanding acoustic interactions with snowpack is vital for geophysical remote sensing and analysis.
Related Concept Videos
00:53Sound Intensity Level
Humans perceive sound by hearing. The human ear helps sound waves reach the brain, which then interprets the waves and creates the perception of hearing. The loudness of the environment in which a person is located determines whether they can distinguish between different sound sources.
The human ear can perceive an extensive range of sound intensity, necessitating the use of the logarithmic scale to define a physical quantity—the intensity level. It is a ratio of two intensities and hence a...
The human ear can perceive an extensive range of sound intensity, necessitating the use of the logarithmic scale to define a physical quantity—the intensity level. It is a ratio of two intensities and hence a...
01:16Shock Waves
While deriving the Doppler formula for the observed frequency of a sound wave, it is assumed that the speed of sound in the medium is greater than the source's speed through it. When this condition is breached, a shock wave occurs.
When the source's speed approaches the speed of sound, constructive interference between successive wavefronts emitted by the source occurs immediately behind it. Initially, scientists believed that this constructive interference would result in such high pressures...
When the source's speed approaches the speed of sound, constructive interference between successive wavefronts emitted by the source occurs immediately behind it. Initially, scientists believed that this constructive interference would result in such high pressures...
01:12Precipitation Processes
The experimental conditions in a gravimetric analysis should be optimized to maximize the particle size and purity of the obtained precipitate. Ideally, the concentration of the precipitating reagent should be low with effective stirring to maintain low relative supersaturation for the growth of large crystals. In homogeneous precipitation, the precipitant is slowly generated by a chemical reaction in the solution to avoid local reagent excesses. For example, urea decomposes gradually to...
01:17Sound as Pressure Waves
Sound waves, which are longitudinal waves, can be modeled as the displacement amplitude varying as a function of the spatial and temporal coordinates. As a column of the medium is displaced, its successive columns are also displaced. As the successive displacements differ relatively, a pressure difference with the surrounding pressure is created. The gauge pressure varies across the medium.
The pressure fluctuation depends on the difference in displacements between the successive points in the...
The pressure fluctuation depends on the difference in displacements between the successive points in the...
01:05Intensity and Pressure of Sound Waves
The intensity of sound waves can be related to displacement and pressure amplitudes by using their wave expressions and the definition of intensity. The critical step to achieve this is to write the power delivered by the particles on the wave as the product of force and velocity and simplify the force per unit area as the pressure. The velocity of the medium's particles can be derived from the displacement.
Unlike the time average of a sinusoidal term, which is zero since it is positive and...
Unlike the time average of a sinusoidal term, which is zero since it is positive and...
01:26Impact: Problem Solving
In an experiment conducted during a Mars mission, a rover propels a projectile with an initial velocity, and the projectile rebounds after colliding with the Martian surface. To ascertain the maximum height attained by the projectile after this collision, the known restitution coefficient and acceleration due to gravity are employed.
By designating the launch point as the origin and utilizing kinematic equations, the vertical component of the projectile's velocity at the point of impact is...
By designating the launch point as the origin and utilizing kinematic equations, the vertical component of the projectile's velocity at the point of impact is...