The detection and correction of snow water equivalent pressure sensor errors
The detection and correction of snow water equivalent pressure sensor errors
复制标题
雪水当量压力传感器误差的检测与修正
DOI：
10.1002/hyp.5795
复制
发表时间：
2004
影响因子：
3.2
通讯作者：
D. Marks
中科院分区：
文献类型：
--
作者：
Jerome B. Johnson;D. Marks
雪水当量（SWE）传感器在积雪底部处于融化温度时可能会出现误差，雪可以承受剪切应力（假设密度大于200 kg m - 3），并且传感器上的融雪速率与周围地面上的不同。在积雪从冬季向春季过渡的关键时刻和快速融雪期开始时，可能出现测量不足或测量过高的误差。确定SWE传感器欠测量误差开始的参数由SWE的负变化率、雪密度的负变化率和雪深的增加来定义。当雪深减小，雪密度变化率超过定义的正阈值时，SWE的变化率将为正。当雪温和雪密度误差条件以及三个测量误差不足或超过指标参数同时满足时，SWE传感器误差开始。误差的实时校正是通过将误差开始时设置的平均积雪密度与雪深相乘来完成的。一旦错误事件结束，当修正后的SWE和SWE传感器数据相交时，SWE再次从SWE传感器测量值中确定。当高质量的SWE传感器、雪或空气温度和雪深测量可用时，可以准确地检测和纠正位于海洋和山间气候带的五种不同传感器的SWE传感器误差。实现误差检测和校正方法需要同时测量SWE、雪深和近地面雪温。通过结合降水数据和由于雨水滞留或融雪造成的雪密度估计，可以改进误差校正。版权所有©2004 John Wiley & Sons， Ltd
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−3), and the rate of snowmelt on the sensor is different than on the surrounding ground. Either undermeasurement or overmeasurement errors may occur at critical times when the snow cover transitions from winter to spring conditions and at the start of periods of rapid snowmelt. Parameters to determine the onset of SWE sensor undermeasurement errors are defined by a negative rate of change for SWE, a negative rate of change for snow density, and an increasing snow depth. For the onset of overmeasurement errors, the rate of change for SWE will be positive while snow depth decreases and the snow density rate of change exceeds a defined positive threshold. When the snow temperature and density error conditions and the three under‐ or over‐measurement error‐indicator parameters are satisfied at the same time, an SWE sensor error has started. Real‐time correction of the errors is done by multiplying the average snow cover density, set at the start of the error, with the snow depth. Once the error event ends, when the corrected SWE and SWE sensor data intersect, SWE is again determined from SWE sensor measurements. SWE sensor errors were accurately detected and corrected for five different sensors located in maritime and intermountain climatic zones when high‐quality SWE sensor, snow or air temperature, and snow depth measurements were available. Implementation of the error detection and correction method requires simultaneous measurements of SWE, snow depth, and snow temperature near the ground. Improved error correction can be achieved by incorporating precipitation data and estimates of snow density due to retained rain or snow melt. Copyright © 2004 John Wiley & Sons, Ltd.