Sediment plume response to surface melting and supraglacial lake drainages on the Greenland ice sheet
Sediment plume response to surface melting and supraglacial lake drainages on the Greenland ice sheet
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沉积物羽流对格陵兰冰盖表面融化和冰上湖排水的响应
DOI：
10.3189/002214309790794904
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发表时间：
2009
影响因子：
3.4
通讯作者：
N. Reeh
中科院分区：
文献类型：
--
作者：
V. Chu;L. Smith;Å. Rennermalm;R. Forster;J. Box;N. Reeh
格陵兰冰盖质量损失的增加以及由此推断的对海平面上升的贡献，增加了对从冰盖流出的融水进行水文观测的需要。我们通过比较：(1)中分辨率成像光谱仪（MODIS）图像和野外数据的羽流面积和悬沙浓度，探讨了冰盖表面水文的时间变化是否与Kangerlussuaq峡湾下游沉积物羽流的发育有关；(2) Special Sensor Microwave/Imager （SSM/I）被动微波数据的冰盖融化程度；(3) MODIS的冰上湖排水事件。结果证实，沉积物羽流的起源是冰盖融化的水释放。羽流面积的年际变化反映了地表融化的年际变化。只要河口没有陆地海冰，随着季节性表面融化的开始，羽流几乎立即出现。融化范围和羽流面积之间的季节性滞后表明沉积物供应在季末枯竭。羽流对冰川上事件的敏感性分析不太确定，69%的熔体脉冲和38%的湖泊排水事件触发了羽流面积的增加。我们的结论是，沉积物羽流行为的遥感提供了一种新的工具，用于检测冰盖融水释放的存在，时间和年际变化。
Increased mass losses from the Greenland ice sheet and inferred contributions to sea-level rise have heightened the need for hydrologic observations of meltwater exiting the ice sheet. We explore whether temporal variations in ice-sheet surface hydrology can be linked to the development of a downstream sediment plume in Kangerlussuaq Fjord by comparing: (1) plume area and suspended sediment concentration from Moderate Resolution Imaging Spectroradiometer (MODIS) imagery and field data; (2) ice-sheet melt extent from Special Sensor Microwave/Imager (SSM/I) passive microwave data; and (3) supraglacial lake drainage events from MODIS. Results confirm that the origin of the sediment plume is meltwater release from the ice sheet. Interannual variations in plume area reflect interannual variations in surface melting. Plumes appear almost immediately with seasonal surface-melt onset, provided the estuary is free of landfast sea ice. A seasonal hysteresis between melt extent and plume area suggests late-season exhaustion in sediment supply. Analysis of plume sensitivity to supraglacial events is less conclusive, with 69% of melt pulses and 38% of lake drainage events triggering an increase in plume area. We conclude that remote sensing of sediment plume behavior offers a novel tool for detecting the presence, timing and interannual variability of meltwater release from the ice sheet.
影响因子：
5.2
作者：
A. Shepherd;A. Hubbard;P. Nienow;Matt A. King;M. McMillan;I. Joughin
通讯作者：
A. Shepherd;A. Hubbard;P. Nienow;Matt A. King;M. McMillan;I. Joughin