DOI: 10.5194/tc-10-1965-2016
Scopus记录号: 2-s2.0-84986570857
论文题名: Application of GRACE to the assessment of model-based estimates of monthly Greenland Ice Sheet mass balance (2003-2012)
作者: Schlegel N ; -J ; , Wiese D ; N ; , Larour E ; Y ; , Watkins M ; M ; , Box J ; E ; , Fettweis X ; , Van Den Broeke M ; R
刊名: Cryosphere
ISSN: 19940416
出版年: 2016
卷: 10, 期: 5 起始页码: 1965
结束页码: 1989
语种: 英语
英文关键词: assessment method
; atmosphere-ice-ocean system
; Bayesian analysis
; climate change
; glacier mass balance
; GRACE
; ice sheet
; quantitative analysis
; regional climate
; sea level
; sea level change
; sensitivity analysis
; spatial resolution
; temporal analysis
; Arctic
; Greenland
; Greenland Ice Sheet
英文摘要: Quantifying the Greenland Ice Sheet's future contribution to sea level rise is a challenging task that requires accurate estimates of ice sheet sensitivity to climate change. Forward ice sheet models are promising tools for estimating future ice sheet behavior, yet confidence is low because evaluation of historical simulations is challenging due to the scarcity of continental-wide data for model evaluation. Recent advancements in processing of Gravity Recovery and Climate Experiment (GRACE) data using Bayesian-constrained mass concentration ("mascon") functions have led to improvements in spatial resolution and noise reduction of monthly global gravity fields. Specifically, the Jet Propulsion Laboratory's JPL RL05M GRACE mascon solution (GRACE-JPL) offers an opportunity for the assessment of model-based estimates of ice sheet mass balance (MB) at ∼ 300km spatial scales. Here, we quantify the differences between Greenland monthly observed MB (GRACE-JPL) and that estimated by state-of-the-art, high-resolution models, with respect to GRACE-JPL and model uncertainties. To simulate the years 2003-2012, we force the Ice Sheet System Model (ISSM) with anomalies from three different surface mass balance (SMB) products derived from regional climate models. Resulting MB is compared against GRACE-JPL within individual mascons. Overall, we find agreement in the northeast and southwest where MB is assumed to be primarily controlled by SMB. In the interior, we find a discrepancy in trend, which we presume to be related to millennial-scale dynamic thickening not considered by our model. In the northwest, seasonal amplitudes agree, but modeled mass trends are muted relative to GRACE-JPL. Here, discrepancies are likely controlled by temporal variability in ice discharge and other related processes not represented by our model simulations, i.e., hydrological processes and ice-ocean interaction. In the southeast, GRACE-JPL exhibits larger seasonal amplitude than predicted by the models while simultaneously having more pronounced trends; thus, discrepancies are likely controlled by a combination of missing processes and errors in both the SMB products and ISSM. At the margins, we find evidence of consistent intra-annual variations in regional MB that deviate distinctively from the SMB annual cycle. Ultimately, these monthly-scale variations, likely associated with hydrology or ice-ocean interaction, contribute to steeper negative mass trends observed by GRACE-JPL. Thus, models should consider such processes at relatively high (monthly-to-seasonal) temporal resolutions to achieve accurate estimates of Greenland MB. © Author(s) 2016. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75085
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: University of California, Los Angeles, Los Angeles, CA, United States; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States; Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, København, Denmark; University of Liège, Department of Geography, Liège, Belgium; Institute for Marine and Atmospheric Research Utrecht (IMAU), Utrecht University, Utrecht, Netherlands
Recommended Citation:
Schlegel N,-J,, Wiese D,et al. Application of GRACE to the assessment of model-based estimates of monthly Greenland Ice Sheet mass balance (2003-2012)[J]. Cryosphere,2016-01-01,10(5)