气候变化领域集成服务门户(CCPortal): ICESat laser altimetry over small mountain glaciers

CCPortal

DOI	10.5194/tc-10-2129-2016
	ICESat laser altimetry over small mountain glaciers
	Treichler D.; Kääb A.
发表日期	2016
ISSN	19940416
卷号	10 期号:5
英文摘要	Using sparsely glaciated southern Norway as a case study, we assess the potential and limitations of ICESat laser altimetry for analysing regional glacier elevation change in rough mountain terrain. Differences between ICESat GLAS elevations and reference elevation data are plotted over time to derive a glacier surface elevation trend for the ICESat acquisition period 2003-2008. We find spatially varying biases between ICESat and three tested digital elevation models (DEMs): the Norwegian national DEM, SRTM DEM, and a high-resolution lidar DEM. For regional glacier elevation change, the spatial inconsistency of reference DEMs - a result of spatio-temporal merging - has the potential to significantly affect or dilute trends. Elevation uncertainties of all three tested DEMs exceed ICESat elevation uncertainty by an order of magnitude, and are thus limiting the accuracy of the method, rather than ICESat uncertainty. ICESat matches glacier size distribution of the study area well and measures small ice patches not commonly monitored in situ. The sample is large enough for spatial and thematic subsetting. Vertical offsets to ICESat elevations vary for different glaciers in southern Norway due to spatially inconsistent reference DEM age. We introduce a per-glacier correction that removes these spatially varying offsets, and considerably increases trend significance. Only after application of this correction do individual campaigns fit observed in situ glacier mass balance. Our correction also has the potential to improve glacier trend significance for other causes of spatially varying vertical offsets, for instance due to radar penetration into ice and snow for the SRTM DEM or as a consequence of mosaicking and merging that is common for national or global DEMs. After correction of reference elevation bias, we find that ICESat provides a robust and realistic estimate of a moderately negative glacier mass balance of around -0.36 ± 0.07 m ice per year. This regional estimate agrees well with the heterogeneous but overall negative in situ glacier mass balance observed in the area. © Author(s) 2016.
学科领域	digital elevation model; elevation; glacier dynamics; glacier mass balance; GLAS; ICESat; laser method; lidar; mountain region; satellite altimetry; Shuttle Radar Topography Mission; spatiotemporal analysis; Norway
语种	英语
scopus关键词	digital elevation model; elevation; glacier dynamics; glacier mass balance; GLAS; ICESat; laser method; lidar; mountain region; satellite altimetry; Shuttle Radar Topography Mission; spatiotemporal analysis; Norway
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/119580
作者单位	Institute of Geosciences, University of Oslo, P.O. Box 1047, Oslo, 0316, Norway
推荐引用方式 GB/T 7714	Treichler D.,Kääb A.. ICESat laser altimetry over small mountain glaciers[J],2016,10(5).
APA	Treichler D.,&Kääb A..(2016).ICESat laser altimetry over small mountain glaciers.Cryosphere,10(5).
MLA	Treichler D.,et al."ICESat laser altimetry over small mountain glaciers".Cryosphere 10.5(2016).