HR: 1340h
AN: C23A-1144    [Abstracts]
TI: How well do observations on bench mark glaciers represent a glacier system?
AU: * Khalsa, S S
EM: sjsk@nsidc.org
AF: National Snow and Ice Data Center, Univ. of Colorado Campus Box 449, Boulder, CO 80309 United States
AU: Raup, B H
EM: braup@nsidc.org
AF: National Snow and Ice Data Center, Univ. of Colorado Campus Box 449, Boulder, CO 80309 United States
AU: Dyurgerov, M
EM: Mark.Dyurgerov@Colorado.EDU
AF: Institute of Arctic and Alpine Research, Univ. of Colorado Campus Box 450, Boulder, CO 80309 United States
AB: The main source of uncertainty in knowledge of the global glacier regime is the limited number of direct mass balance observations. Since the spatial variability of glacier properties is huge the few benchmark glaciers chosen for continuous observations are unlikely to adequately represent the glacier system to which they belong. It is not feasible to suggest that the number of field-based observations will substantially increase in the future. Therefore, observations from space-based sensors will become more widely used to study the characteristics and status of the world's glaciers. In this paper we examine how the restricted number of mass balance observations in one well-monitored glacier system may be used to characterize the entire system, and examine the potential and limitations of monitoring glacier systems from space. We have developed a "template method" whereby mass balance measurements on a benchmark glacier can be extrapolated to estimate the mass balance of its glacier system. We test this method by applying it to the Scandinavia Glacier System (SGS), where standard and continuous mass balance observations have been carried out since the mid-20th century on several tens of glaciers. We analyze spatial variability of glacier mass balance, accumulation area ratio, ELA and hypsography for twenty benchmark glaciers in SGS to better understand the behavior of this glacier system, and connect the standard field measurement results to estimations of ELA from Landsat imagery. From this we estimate the mass balance of SGS, and predict extreme values in relation to climate change. We have found that only a few glaciers in this system may adequately represent the regime of SGS, and that those commonly believed to be representative are actually not. We quantify the uncertainty in the extrapolation.
DE: 0720 Glaciers
SC: Cryosphere [C]
MN: Fall Meeting 2005