DOI: 10.5194/tc-14-633-2020
论文题名: Glacial-cycle simulations of the Antarctic Ice Sheet with the Parallel Ice Sheet Model (PISM)-Part 2: Parameter ensemble analysis
作者: Albrecht T. ; Winkelmann R. ; Levermann A.
刊名: Cryosphere
ISSN: 19940416
出版年: 2020
卷: 14, 期: 2 起始页码: 633
结束页码: 656
语种: 英语
英文关键词: glacial-interglacial cycle
; last deglaciation
; Last Glacial Maximum
; meltwater
; parameter estimation
; sea level change
; simulation
; Antarctic Ice Sheet
; Antarctica
英文摘要: The Parallel Ice Sheet Model (PISM) is applied to the Antarctic Ice Sheet over the last two glacial cycles ( ≈ 210 000 years) with a resolution of 16 km. An ensemble of 256 model runs is analyzed in which four relevant model parameters have been systematically varied using fullfactorial parameter sampling. Parameters and plausible parameter ranges have been identified in a companion paper (Albrecht et al., 2020) and are associated with ice dynamics, climatic forcing, basal sliding and bed deformation and represent distinct classes of model uncertainties. The model is scored against both modern and geologic data, including reconstructed grounding-line locations, elevation-age data, ice thickness, surface velocities and uplift rates. An aggregated score is computed for each ensemble member that measures the overall model-data misfit, including measurement uncertainty in terms of a Gaussian error model (Briggs and Tarasov, 2013). The statistical method used to analyze the ensemble simulation results follows closely the simple averaging method described in Pollard et al. (2016). This analysis reveals clusters of best-fit parameter combinations, and hence a likely range of relevant model and boundary parameters, rather than individual best-fit parameters. The ensemble of reconstructed histories of Antarctic Ice Sheet volumes provides a score-weighted likely range of sealevel contributions since the Last Glacial Maximum (LGM) of 9:4±4:1m (or 6:5±2:0×106 km3), which is at the upper range of most previous studies. The last deglaciation occurs in all ensemble simulations after around 12 000 years before present and hence after the meltwater pulse 1A (MWP1a). Our ensemble analysis also provides an estimate of parametric uncertainty bounds for the present-day state that can be used for PISM projections of future sea-level contributions from the Antarctic Ice Sheet. © Author(s) 2020. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164388
Appears in Collections: 气候变化与战略
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作者单位: Potsdam Institute for Climate Impact Research (PIK), Member of the Leibniz Association, P.O. Box 601203, Potsdam, 14412, Germany; University of Potsdam, Institute of Physics and Astronomy, Karl-Liebknecht-Str. 24-25, Potsdam, 14476, Germany; Lamont-Doherty Earth Observatory, Columbia University, New York, United States
Recommended Citation:
Albrecht T.,Winkelmann R.,Levermann A.. Glacial-cycle simulations of the Antarctic Ice Sheet with the Parallel Ice Sheet Model (PISM)-Part 2: Parameter ensemble analysis[J]. Cryosphere,2020-01-01,14(2)