TY - Generic T1 - Research and Development in Advancing Fluidless Snow Water Content Monitoring T2 - 86th Annual Western Snow Conference Y1 - 2018 A1 - Heggli, Anne A1 - Heggli, Matthew A1 - Trauman, Todd AB -

The U.S. Department of Agriculture (USDA) has coordinated the cooperative effort in snow surveying and water supply forecasting in the Western States since 1935. This initially involved the Research and Development (R&D) of progressive snowpack monitoring techniques, eventually bringing automated measurements that transmitted data directly to their office. The advances in snowpack monitoring provided more reliable and timely forecasts vital for farmers, business owners, and communities. The technology that is currently used to continuously measure Snow Water Equivalent (SWE), the snow pillow, was developed in the 1960’s, over 50 years ago. The snow pillow has been the only reliable SWE sensor despite the inherent limitations. With limited improvements in SWE monitoring to date, Alpine Hydromet set out to develop technology towards bringing a better solution for operators. This summarizes the R&D of two SWE sensors that aim to phase out the traditional fluid snow pillow while developing more reliable and robust technologies; the Fluidless Snow Pillow (FSP) and Cosmic Ray Detector (CRD). This analysis presents an indepth analysis of comparative data from the winter of 2016-17 and 2017-18 (partial winter through April, 2018) as tested at the UC Berkeley Central Sierra Snow Laboratory (CSSL). (KEYWORDS: snow water content, snow pillow, fluidless snow pillow, cosmic ray)

JF - 86th Annual Western Snow Conference CY - Albuquerque, New Mexico UR - /files/PDFs/2018Heggli.pdf ER - TY - Generic T1 - Data Analysis of the Snow Pack Analyzing System Tested by UCAR T2 - 81st Annual Western Snow Conference Y1 - 2013 A1 - Heggli, Anne KW - liquid water KW - snow pack KW - Snow water equivalent KW - SWE AB -

Snow pack measurements can be costly to perform and generally provide only snow water equivalent (SWE) and snow depth from which density can be calculated and the onset of snow melt can be estimated. A new automatic snow pack analyzing system designed by Sommer Systemtechnik in Koblach, Austria has developed new technology to measure snow pack characteristics. The instrument is an automatic in-situ measurement system that determines the percentage of liquid water and ice by measuring the “complex” impedance from which SWE is determined. However, the liquid water content as a percentage is a value that has never been able to be measured before.

This Snow Pack Analyzing system or SPA system, as it is referred to, was installed at the (University Corporation for Atmospheric Research (UCAR) Test Field site in March of 2012 where it could be collocated and compared to conventional snow tube and snow pillow measurements. This manuscript will describe the measurement principal of the SPA system as well as the parameters that can be derived, including indicators to help improve the prediction of snow melt. Preliminary results from the UCAR Test Field site installation comparing the SPA system to both the snow tube and snow pillow measurement will also be presented. It is reasonable to conclude the SPA system can be a valuable addition to existing snow melt forecasting schemes.

JF - 81st Annual Western Snow Conference T3 - Proceedings of the Western Snow Conference CY - Jackson Hole, Wyoming UR - sites/westernsnowconference.org/PDFs/2013Heggli.pdf ER -