气候变化领域集成服务门户(CCPortal): Application of a two-step approach for mapping ice thickness to various glacier types on Svalbard

CCPortal

DOI	10.5194/tc-11-2003-2017
	Application of a two-step approach for mapping ice thickness to various glacier types on Svalbard
	Jakob Fürst J.; Gillet-Chaulet F.; Benham T.J.; Dowdeswell J.A.; Grabiec M.; Navarro F.; Pettersson R.; Moholdt G.; Nuth C.; Sass B.; Aas K.; Fettweis X.; Lang C.; Seehaus T.; Braun M.
发表日期	2017
ISSN	19940416
卷号	11 期号:5
英文摘要	The basal topography is largely unknown beneath most glaciers and ice caps, and many attempts have been made to estimate a thickness field from other more accessible information at the surface. Here, we present a two-step reconstruction approach for ice thickness that solves mass conservation over single or several connected drainage basins. The approach is applied to a variety of test geometries with abundant thickness measurements including marine- and land-terminating glaciers as well as a 2400-km2 ice cap on Svalbard. The input requirements are kept to a minimum for the first step. In this step, a geometrically controlled, non-local flux solution is converted into thickness values relying on the shallow ice approximation (SIA). In a second step, the thickness field is updated along fast-flowing glacier trunks on the basis of velocity observations. Both steps account for available thickness measurements. Each thickness field is presented together with an error-estimate map based on a formal propagation of input uncertainties. These error estimates point out that the thickness field is least constrained near ice divides or in other stagnant areas. Withholding a share of the thickness measurements, error estimates tend to overestimate mismatch values in a median sense. We also have to accept an aggregate uncertainty of at least 25-% in the reconstructed thickness field for glaciers with very sparse or no observations. For Vestfonna ice cap (VIC), a previous ice volume estimate based on the same measurement record as used here has to be corrected upward by 22-%. We also find that a 13-% area fraction of the ice cap is in fact grounded below sea level. The former 5-% estimate from a direct measurement interpolation exceeds an aggregate maximum range of 6-23-% as inferred from the error estimates here.
学科领域	drainage basin; glacier; ice cap; ice thickness; interpolation; mapping method; marine environment; measurement method; reconstruction; topography; uncertainty analysis; Arctic; Nordaustlandet; Svalbard; Svalbard and Jan Mayen; Vestfonna
语种	英语
scopus关键词	drainage basin; glacier; ice cap; ice thickness; interpolation; mapping method; marine environment; measurement method; reconstruction; topography; uncertainty analysis; Arctic; Nordaustlandet; Svalbard; Svalbard and Jan Mayen; Vestfonna
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/119342
作者单位	Institute of Geography, University of Erlangen-Nuremberg, Wetterkreuz 15, Erlangen, 91058, Germany; University of Grenoble Alpes, CNRS, IRD, Institut des Géosciences de l'Environnement (IGE), Grenoble, CS 40-700, France; Scott Polar Research Institute, University of Cambridge, Lensfield Road, Cambridge, CB2-1ER, United Kingdom; Faculty of Earth Sciences, University of Silesia in Katowice, ul. Bankowa 12, Katowice, 40-007, Poland; Departamento de Matematica Aplicada A Las Tecnologias de la Informacion y Las Comunicaciones, ETSI de Telecomunicación, Universidad Politécnica de Madrid, Av. Complutense 30, Madrid, 28040, Spain; Department of Earth Sciences, Uppsala University, Geocentrum, Villav. 16, Uppsala, 752-36, Sweden; Norwegian Polar Institute, Fram Centre, P.O. Box 6606 Langnes, Tromsø, 9296, Norway; Department of Geosciences, University of Oslo, P.O. Box 1047, Blindern, Oslo, 0316, Norway; Department of Geography, University of Liège, Quartier Village 4, Clos mercator 3, Liège, 4000, Belgium
推荐引用方式 GB/T 7714	Jakob Fürst J.,Gillet-Chaulet F.,Benham T.J.,et al. Application of a two-step approach for mapping ice thickness to various glacier types on Svalbard[J],2017,11(5).
APA	Jakob Fürst J..,Gillet-Chaulet F..,Benham T.J..,Dowdeswell J.A..,Grabiec M..,...&Braun M..(2017).Application of a two-step approach for mapping ice thickness to various glacier types on Svalbard.Cryosphere,11(5).
MLA	Jakob Fürst J.,et al."Application of a two-step approach for mapping ice thickness to various glacier types on Svalbard".Cryosphere 11.5(2017).