Antarctica
; article
; conceptual framework
; correlation analysis
; glacial mass balance
; growth rate
; ice sheet
; priority journal
; probability
; river basin
; sea level
; sea level rise
; spatial analysis
; statistical parameters
; Antarctic Regions
; Climate Change
; Ice Cover
; Oceans and Seas
; Probability
英文摘要:
Previous sea level rise (SLR) assessments have excluded the potential for dynamic ice loss over much of Greenland and Antarctica, and recently proposed "upper bounds" on Antarctica's 21st-century SLR contribution are derived principally from regions where present-day mass loss is concentrated (basin 15, or B15, drained largely by Pine Island, Thwaites, and Smith glaciers). Here, we present a probabilistic framework for assessing the ice sheet contribution to sea level change that explicitly accounts for mass balance uncertainty over an entire ice sheet. Applying this framework to Antarctica, we find that ongoing mass imbalances in non- B15 basins give an SLR contribution by 2100 that: (i) is comparable to projected changes in B15 discharge and Antarctica's surface mass balance, and (ii) varies widely depending on the subset of basins and observational dataset used in projections. Increases in discharge uncertainty, or decreases in the exceedance probability used to define an upper bound, increase the fractional contribution of non-B15 basins; even weak spatial correlations in future discharge growth rates markedly enhance this sensitivity. Although these projections rely on poorly constrained statistical parameters, they may be updated with observations and/or models at many spatial scales, facilitating a more comprehensive account of uncertainty that, if implemented, will improve future assessments.
Little, C.M., Woodrow Wilson School of Public and International Affairs, Princeton University, Princeton, NJ 08544, United States; Urban, N.M., Woodrow Wilson School of Public and International Affairs, Princeton University, Princeton, NJ 08544, United States, Computational Physics and Methods (CCS-2), Los Alamos National Laboratory, Los Alamos, NM 87545, United States; Oppenheimer, M., Woodrow Wilson School of Public and International Affairs, Princeton University, Princeton, NJ 08544, United States, Department of Geosciences, Princeton University, Princeton, NJ 08544, United States
Recommended Citation:
Little C.M.,Urban N.M.,Oppenheimer M.. Probabilistic framework for assessing the ice sheet contribution to sea level change[J]. Proceedings of the National Academy of Sciences of the United States of America,2013-01-01,110(9)