โ Scribed by Jerome B. Johnson
No coin nor oath required. For personal study only.
A theory of pressure sensor response in snow is derived and used to examine the sources of measurement errors in snow water equivalent (SWE) pressure sensors. Measurement errors in SWE are caused by differences in the compressibility of the pressure sensor and the adjacent snow layer, which produces a shear stress along the perimeter of the sensor. When the temperature at the base of the snow cover equals 0 ยฐC, differences in the snowmelt rate between the snowโSWE sensor interface and the adjacent snowโsoil interface may also produce a shear stress along the sensor's perimeter. This shear stress perturbs the pressure field over the sensor, producing SWE measurement errors. Snow creep acts to reduce shear stresses along the SWE sensor's perimeter at a rate that is inversely proportional to the snow viscosity. For sustained periods of differential snowmelt, a difference in the mass of snow over the sensor compared with the surrounding soil will develop, producing additional permanent errors in SWE measurements. The theory indicates that SWE pressure sensor performance can be improved by designing a sensor with a high Young's modulus (low compressibility), low aspect ratio, large diameter and thermal properties that match those of the surrounding soil. Simulations of SWE pressure sensor errors using the theory are in close agreement with observed errors and may provide a means to correct historical SWE measurements for use in hydrological hindcast or climate studies. Published in 2003 by John Wiley & Sons, Ltd.
๐ SIMILAR VOLUMES
## Abstract Snow water equivalent (SWE) sensors can experience errors when the base of the snow cover is at the melting temperature, the snow can support shear stresses (assumed to occur at densities greater than 200 kg m^โ3^), and the rate of snowmelt on the sensor is different than on the surroun
## Abstract A 5 year field study was conducted to determine the mechanisms that cause snow water equivalent (SWE) pressure sensor measurement errors. The objective is to establish design and installation criteria to develop an accurate electronic SWE pressure sensor that minimizes errors. We monito
## Abstract During the 2006โ2007 winter season, 17 sites across the US including Alaska tested an automated snow measurement system. This article aims to describe successes and failures of this system and provide insight into data collected this season. The system was designed in collaboration with