Identifying Spatial Variability in Greenland's Outlet Glacier Response to Ocean Heat

Frontiers in Digital Humanities

Csatho, Beata M.¹  Cochran, James R.²  Porter, David F.²  Bell, Robin E.²  Tinto, Kirsty J.²  Boghosian, Alexandra L.² 

[1] Department of Geology, University of Buffalo, United States;Marine Geology and Geophysics, Lamont-Doherty Earth Observatory of Columbia University, United States

关键词: Ice thickness measurements;    Ice-ocean interactions;    Ice sheet mass balance;    Glacier geophysics;    spatial statistics;   

DOI  :  10.3389/feart.2018.00090

学科分类：社会科学、人文和艺术（综合）

来源: Frontiers

【 摘 要 】

Although the Greenland ice sheet is losing mass as a whole, patterns of change on both local and regional scales are complex. Spatial statistics reveal large spatial variability of dynamic thinning rates of Greenland's marine-terminating glaciers between 2003 and 2009; only 18% of glacier thinning rates co-vary with neighboring glaciers. Most spatially-correlated thinning rates are clusters of stable glaciers in the Thule, Scoresby Sund, and Southwest regions. Conversely, where spatial-autocorrelation is low, individual glaciers are more strongly controlled by local, glacier-scale features than by regional influences. We investigate possible sources of local control of oceanic forcing by combining grounding line depths and ocean model output to estimate mean ocean heat content adjacent to 74 glaciers. Linear regression models indicate stronger correlation of dynamic thinning rates with ocean heat content compared to those with grounding line depths alone. The correlation between ocean heat and dynamic thinning is robust for all of Greenland except glaciers in the West, and strongest in the Southeast (coefficient of determination of 0.81), implying that glaciers with deeper grounded termini here are most sensitive to changes in ocean forcing. In the Northwest, accounting for shallow sills in the regressions improves the correlation of water depth with glacial thinning, highlighting the need for comprehensive knowledge of fjord geometry.

【 授权许可】

CC BY