Water exchange between the continental shelf and the cavity beneath Nioghalvfjerdsbræ (79 North Glacier)
Wilson, Nathaniel J.
MetadataShow full item record
The mass loss at Nioghalvfjerdsbræ is primarily due to rapid submarine melting. Ocean data obtained from beneath the Nioghalvfjerdsbræ ice tongue show that melting is driven by the presence of warm (1°C) Atlantic Intermediate Water (AIW). A sill prevents AIW from entering the cavity from Dijmphna Sund, requiring that it flow into the cavity via bathymetric channels to the south at a pinned ice front. Comparison of water properties from the cavity, Dijmphna Sund, and the continental shelf support this conclusion. Overturning circulation rates inferred from observed melt rates and cavity stratification suggest an exchange flow between the cavity and the continental shelf of 38mSv, sufficient to flush cavity waters in under 1 year. These results place upper bounds on the timescales of external variability that can be transmitted to the glacier via the ice tongue cavity.
Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 42 (2015): 7648–7654, doi:10.1002/2015GL064944.
Showing items related by title, author, creator and subject.
A science plan for a collaborative international research program on the coupled North Atlantic-Arctic system, a report of a Planning Workshop for an International Research Program on the Coupled North Atlantic-Arctic System developed from a workshop held in Arlington, VA 14-16 April 2014 Hofmann, Eileen E.; St. John, Mike; Benway, Heather M. (Ocean Carbon & Biogeochemistry Program, 2015)This North Atlantic-Arctic science plan is derived from an international workshop held in April 2014 with support from the National Science Foundation Division of Ocean Sciences and the European Union (EU). The workshop ...
Tracing the Nd isotope evolution of North Atlantic Deep and Intermediate Waters in the western North Atlantic since the Last Glacial Maximum from Blake Ridge sediments Gutjahr, Marcus; Frank, Martin; Stirling, Claudine H.; Keigwin, Lloyd D.; Halliday, Alex N. (2007-10-23)A high-resolution authigenic Nd isotope record has been extracted from the Fe-Mn oxyhydroxide fraction of drift sediments along the Blake Ridge in the North Atlantic. These sediments facilitate reconstruction of the timing ...
The impact of the North Atlantic Oscillation on the uptake and accumulation of anthropogenic CO2 by North Atlantic Ocean mode waters Levine, Naomi M.; Doney, Scott C.; Lima, Ivan D.; Wanninkhof, Rik; Bates, Nicholas R.; Feely, Richard A. (American Geophysical Union, 2011-09-21)The North Atlantic Ocean accounts for about 25% of the global oceanic anthropogenic carbon sink. This basin experiences significant interannual variability primarily driven by the North Atlantic Oscillation (NAO). A suite ...