HR: 10:50h
AN: GC32A-03    [Abstracts]
TI: Toward Standardization in Methods and Techniques for Measuring and Monitoring Snowcover Albedo.
AU: * Landry, C C
EM: clandry@snowstudies.org
AF: Center for Snow and Avalanche Studies, PO Box 190 1315 Snowden - Rm 8, Silverton, CO 81433, United States
AU: Painter, T H
EM: painter@geog.utah.edu
AF: University of Utah, Department of Geography 260 S. Central Campus Dr. Rm. 270, Salt Lake City, UT 84112-9155, United States
AU: Barrett, A P
EM: apbarret@kryos.colorado.edu
AF: National Snow and Ice Data Center, University of Colorado CIRES - 449 UCB, Boulder, CO 80309-0449, United States
AU: Cassidy, M
EM: Maureen.Cassidy@colorado.edu
AF: University of Colorado, Department of Geography Guggenheim 110 - 260 UCB, Boulder, CO 80309-0260, United States
AB: Global climate change portends increasing uncertainty regarding the reliability of mountain snow and ice fields as a source of fresh water for one-sixth of the world's population. Standardization of system measurements is required to enhance our understanding of cryospheric responses and forcings. Irrespective of projected temperature trends, we have shown that interactions between deserts and down-wind mountain ranges can and do result in significant advancements of snowmelt timing as well as increased snowmelt intensity, substantially altering regional hydrographs. We have developed and refined methods for monitoring enhanced radiative forcing of snowmelt caused by dust induced reductions in snowcover albedo. In- situ, continuous measurements of snowcover albedo and energy budget parameters are obtained in the Senator Beck Basin Study Area with two arrays of up- and down-looking pyranometers, pyrgeometers, and infrared snow surface temperature sensors. Air temperature, relative humidity, and wind speed are monitored at two heights above the snowcover. Measurements of short wave radiation reflected by the snowpack are corrected for surface geometry by monitoring an array of snow stakes referenced to a level plane. The efficiency of enhanced energy absorption by exposed and near-surface dust layers is monitored using a volumetric sampling design whereby ten snow samples are collected to a depth of 30 cm, near the limit of significant light penetration. Those samples are then processed to quantify the mass of absorbing material per unit of area at a given depth, enabling the estimation of enhanced absorption throughout the near-surface and surface of the snowcover. These methods, in conjunction with traditional snowpack profiling techniques, have proven to be a reliable, practical, and repeatable approach to monitoring the influence of desert dust on mountain hydrology. The enhanced rigor with which these measurements are performed presents a platform upon which to build consensus protocols for adoption in other system monitoring applications and locales.
DE: 0740 Snowmelt
DE: 0764 Energy balance
DE: 0794 Instruments and techniques
DE: 1621 Cryospheric change (0776)
DE: 1630 Impacts of global change (1225)
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting