Characteristics and dynamics of two major Greenland glacial fjords

View/ Open
Date
2014-06-16Author
Sutherland, David A.
Concept link
Straneo, Fiamma
Concept link
Pickart, Robert S.
Concept link
Metadata
Show full item recordCitable URI
https://hdl.handle.net/1912/6860As published
https://doi.org/10.1002/2013JC009786DOI
10.1002/2013JC009786Keyword
Greenland; Fjord circulation; Estuarine circulation; Intermediary circulation; Meltwater; East Greenland Current; Atlantic Water; GlaciersAbstract
The circulation regimes of two major outlet glacial fjords in southeastern Greenland, Sermilik Fjord (SF) and Kangerdlugssuaq Fjord (KF), are investigated using data collected in summer 2009. The two fjords show similar flow patterns, with a time-dependent, vertically sheared flow structure dominating over the background estuarine flow driven by buoyancy input. We show that this time-dependent flow is consistent with circulation induced by density interface fluctuations at the fjord mouth, often referred to as intermediary circulation. One difference between the fjords is that the hydrographic and velocity structure below a surface modified layer is found to be three layer in KF in summer, compared to two layer in SF. Outside each fjord, large-scale geostrophic currents dictate the stratification at the mouth, although the way in which these large-scale flows impinge on each fjord is distinct. Combining the observations with estimates from existing theories, we find the magnitudes of the estuarine (Qe) and intermediary (Qi) circulation and show that Qi >> Qe, although along-fjord winds can also be significant. We expect that the critical parameter determining Qi/Qe is the sill depth compared to the fjord depth, with shallower sills corresponding to weaker intermediary circulation. Finally, we discuss the implications of strong intermediary circulation on calculating heat transport to the glacier face and its potential feedbacks on the background circulation in these highly stratified estuaries.
Description
Author Posting. © American Geophysical Union, 2014. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 119 (2014): 3767–3791, doi:10.1002/2013JC009786.
Collections
Suggested Citation
Journal of Geophysical Research: Oceans 119 (2014): 3767–3791Related items
Showing items related by title, author, creator and subject.
-
Heat, salt, and freshwater budgets for a glacial fjord in Greenland
Jackson, Rebecca H.; Straneo, Fiamma (American Meteorological Society, 2016-09-01)In Greenland’s glacial fjords, heat and freshwater are exchanged between glaciers and the ocean. Submarine melting of glaciers has been implicated as a potential trigger for recent glacier acceleration, and observations ... -
Export of strongly diluted Greenland meltwater from a major glacial fjord
Beaird, Nicholas; Straneo, Fiamma; Jenkins, William J. (John Wiley & Sons, 2018-05-05)The Greenland Ice Sheet has been, and will continue, losing mass at an accelerating rate. The influence of this anomalous meltwater discharge on the regional and large‐scale ocean could be considerable but remains poorly ... -
Quantifying flow regimes in a Greenland glacial fjord using iceberg drifters
Sutherland, David A.; Roth, George E.; Hamilton, Gordon S.; Mernild, Sebastian H.; Stearns, Leigh A.; Straneo, Fiamma (John Wiley & Sons, 2014-12-11)Large, deep-keeled icebergs are ubiquitous in Greenland's outlet glacial fjords. Here we use the movement of these icebergs to quantify flow variability in Sermilik Fjord, southeast Greenland, from the ice mélange through ...