Updated estimates of glacier volume changes in the western Chugach Mountains, Alaska, and a comparison of regional extrapolation methods

Abstract

[1] We used airborne altimetry measurements to determine the volume changes of 23 glaciers in the western Chugach Mountains, Alaska, United States, between 1950/1957. Average net balance rates ranged between À3.1 to 0.16 m yr À1 for the tidewater and À1.5 to À0.02 m yr À1 for the nontidewater glaciers. We tested several methods for extrapolating these measurements to all the glaciers of the western Chugach Mountains using a process similar to cross validation. Predictions of individual glacier changes appear to be difficult, probably because of the effects of glacier dynamics, which on long (multidecadal) timescales, complicates the response of glaciers to climate. In contrast, estimates of regional contributions to rising sea level were similar for different methods, mainly because the large glaciers, whose changes dominated the regional total, were among those measured. For instance, the above sea level net balance rate of Columbia glacier (À3.1 ± 0.08 km 3 yr À1 water equivalent (weq) or an equivalent rise in sea level (SLE) of 0.0090 ± 0.0002 mm yr

Extrapolating glacier mass balance to the mountain-range scale: the European Alps 1900–2100

“…This concept is similar to extrapolating the mean of observed centerline surface elevation changes in altitude bands to unmeasured glaciers as proposed by Arendt et al (2006). Here, 100-yr mean mass balance of the data sets presented by Huss et al (2010a,b) is averaged in 100 m elevation bands in a first step.…”

“…Extrapolation of single-glacier mass balance series to several thousand glaciers within a mountain range is not trivial and involves considerable uncertainties (e.g. Arendt et al, 2006). Differences in mass balance between neighbouring glaciers are more importantly controlled by glacier geometry than by regional climate variability; mass balance response to similar changes in forcing can differ by up to a factor of four (Kuhn et al, 1985;Abermann et al, 2011b;.…”

“…The methodology suggested by Cogley (2005) applies a spatial interpolation algorithm that fits two-dimensional polynomials to the single-glacier observations. Arendt et al (2006) compare four different approaches for the regionalization of glacier mass change in the Chugach Published by Copernicus Publications on behalf of the European Geosciences Union.…”

Forecasting temperate alpine glacier survival from accumulation zone observations

“…The well documented pattern of thickness change along a longitudinal profile of a land terminating glacier is greatest thinning at the terminus, and at some distance above the terminus, usually in the accumulation zone, the glacier thins significantly less even during retreat (Paterson, 1981;Schwitter and Raymond, 1993). Arendt et al (2006) observed from repeat longitudinal profiles of glaciers in Alaska near zero changes at higher elevations, decreasing to a maximum rate of thinning at the elevation of the terminus. Johannesson et al (1989) and Schwitter and Raymond (1993) described a profile shape parameter f , this factor is a measure of the degree to which thickness change, h, is distributed along the length of a glacier.…”

Surge dynamics on Bering Glacier, Alaska, in 2008–2011

“…The University of Alaska Fairbanks (UAF) Laser Altimetry Program has flown repeat centerline surface elevation profiles on over 200 glaciers across Alaska and adjoining Canada since 1993 Arendt et al, 2002Arendt et al, , 2006. Centerline profiles of the BGS were flown in June 1995and 2000, in August 2000, 2007, in September 2008and in August 2009 (Koenig et al, 2010).…”