DOI: 10.5194/tc-10-2953-2016
Scopus记录号: 2-s2.0-85002323059
论文题名: Improved retrieval of land ice topography from CryoSat-2 data and its impact for volume-change estimation of the Greenland Ice Sheet
作者: Nilsson J ; , Gardner A ; , Sørensen L ; S ; , Forsberg R
刊名: Cryosphere
ISSN: 19940416
出版年: 2016
卷: 10, 期: 6 起始页码: 2953
结束页码: 2969
语种: 英语
英文关键词: airborne sensing
; annual variation
; CryoSat
; dielectric property
; estimation method
; GLAS
; heterogeneity
; ice sheet
; ICESat
; interferometry
; methodology
; sensitivity analysis
; spatial analysis
; topography
; volume change
; Arctic
; Greenland
; Greenland Ice Sheet
英文摘要: A new methodology for retrieval of glacier and ice sheet elevations and elevation changes from CryoSat-2 data is presented. Surface elevations and elevation changes determined using this approach show significant improvements over ESA's publicly available CryoSat-2 elevation product (L2 Baseline-B). The results are compared to near-coincident airborne laser altimetry from NASA's Operation IceBridge and seasonal height amplitudes from the Ice, Cloud, and Elevation Satellite (ICESat). Applying this methodology to CryoSat-2 data collected in interferometric synthetic aperture mode (SIN) over the high-relief regions of the Greenland Ice Sheet we find an improvement in the root-mean-square error (RMSE) of 27 and 40% compared to ESA's L2 product in the derived elevation and elevation changes, respectively. In the interior part of the ice sheet, where CryoSat-2 operates in low-resolution mode (LRM), we find an improvement in the RMSE of 68 and 55% in the derived elevation and elevation changes, respectively. There is also an 86% improvement in the magnitude of the seasonal amplitudes when compared to amplitudes derived from ICESat data. These results indicate that the new methodology provides improved tracking of the snow/ice surface with lower sensitivity to changes in near-surface dielectric properties. To demonstrate the utility of the new processing methodology we produce elevations, elevation changes, and total volume changes from CryoSat-2 data for the Greenland Ice Sheet during the period January 2011 to January 2015. We find that the Greenland Ice Sheet decreased in volume at a rate of 289 ± 20km3 a-1, with high interannual variability and spatial heterogeneity in rates of loss. This rate is 65km3 a-1 more negative than rates determined from ESA's L2 product, highlighting the importance of CryoSat-2 processing methodologies. © Author(s) 2016. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75027
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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作者单位: Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States; DTU Space, National Space Institute, Technical University of Denmark, Kgs. Lyngby, Denmark
Recommended Citation:
Nilsson J,, Gardner A,, Sørensen L,et al. Improved retrieval of land ice topography from CryoSat-2 data and its impact for volume-change estimation of the Greenland Ice Sheet[J]. Cryosphere,2016-01-01,10(6)