Heat, salt, and freshwater budgets for a glacial fjord in Greenland
Author Posting. © American Meteorological Society, 2016. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 46 (2016): 2735-2768, doi:10.1175/JPO-D-15-0134.1....
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ftwhoas:oai:darchive.mblwhoilibrary.org:1912/8491 2023-05-15T16:21:29+02:00 Heat, salt, and freshwater budgets for a glacial fjord in Greenland Jackson, Rebecca H. Straneo, Fiamma 2016-09-01 https://hdl.handle.net/1912/8491 en_US eng American Meteorological Society https://doi.org/10.1175/JPO-D-15-0134.1 Journal of Physical Oceanography 46 (2016): 2735-2768 https://hdl.handle.net/1912/8491 doi:10.1175/JPO-D-15-0134.1 Journal of Physical Oceanography 46 (2016): 2735-2768 doi:10.1175/JPO-D-15-0134.1 Geographic location/entity Estuaries Glaciers Circulation/ Dynamics Coastal flows Atm/Ocean Structure/ Phenomena Freshwater Snowmelt/icemelt Observational techniques and algorithms In situ oceanic observations Article 2016 ftwhoas https://doi.org/10.1175/JPO-D-15-0134.1 2022-05-28T22:59:45Z Author Posting. © American Meteorological Society, 2016. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 46 (2016): 2735-2768, doi:10.1175/JPO-D-15-0134.1. 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 of ocean heat transport are increasingly being used to infer the submarine melt rates. The complete heat, salt, and mass budgets that underlie such methods, however, have been largely neglected. Here, a new framework for exploring glacial fjord budgets is developed. Building on estuarine studies of salt budgets, the heat, salt, and mass transports through the fjord are decomposed, and new equations for calculating freshwater fluxes from submarine meltwater and runoff are presented. This method is applied to moored records from Sermilik Fjord, near the terminus of Helheim Glacier, to evaluate the dominant balances in the fjord budgets and to estimate freshwater fluxes. Throughout the year, two different regimes are found. In the nonsummer months, advective transports are balanced by changes in heat/salt storage within their ability to measure; freshwater fluxes cannot be inferred as a residual. In the summer, a mean exchange flow emerges, consisting of inflowing Atlantic water and outflowing glacially modified water. This exchange transports heat toward the glacier and is primarily balanced by changes in storage and latent heat for melting ice. The total freshwater flux increases over the summer, reaching 1200 ± 700 m3 s−1 of runoff and 1500 ± 500 m3 s−1 of submarine meltwater from glaciers and icebergs in August. The methods and results highlight important components of fjord budgets, particularly the storage and barotropic terms, that have been not been appropriately considered in previous estimates ... Article in Journal/Newspaper glacier Greenland Sermilik Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) Greenland Journal of Physical Oceanography 46 9 2735 2768 |
institution |
Open Polar |
collection |
Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) |
op_collection_id |
ftwhoas |
language |
English |
topic |
Geographic location/entity Estuaries Glaciers Circulation/ Dynamics Coastal flows Atm/Ocean Structure/ Phenomena Freshwater Snowmelt/icemelt Observational techniques and algorithms In situ oceanic observations |
spellingShingle |
Geographic location/entity Estuaries Glaciers Circulation/ Dynamics Coastal flows Atm/Ocean Structure/ Phenomena Freshwater Snowmelt/icemelt Observational techniques and algorithms In situ oceanic observations Jackson, Rebecca H. Straneo, Fiamma Heat, salt, and freshwater budgets for a glacial fjord in Greenland |
topic_facet |
Geographic location/entity Estuaries Glaciers Circulation/ Dynamics Coastal flows Atm/Ocean Structure/ Phenomena Freshwater Snowmelt/icemelt Observational techniques and algorithms In situ oceanic observations |
description |
Author Posting. © American Meteorological Society, 2016. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 46 (2016): 2735-2768, doi:10.1175/JPO-D-15-0134.1. 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 of ocean heat transport are increasingly being used to infer the submarine melt rates. The complete heat, salt, and mass budgets that underlie such methods, however, have been largely neglected. Here, a new framework for exploring glacial fjord budgets is developed. Building on estuarine studies of salt budgets, the heat, salt, and mass transports through the fjord are decomposed, and new equations for calculating freshwater fluxes from submarine meltwater and runoff are presented. This method is applied to moored records from Sermilik Fjord, near the terminus of Helheim Glacier, to evaluate the dominant balances in the fjord budgets and to estimate freshwater fluxes. Throughout the year, two different regimes are found. In the nonsummer months, advective transports are balanced by changes in heat/salt storage within their ability to measure; freshwater fluxes cannot be inferred as a residual. In the summer, a mean exchange flow emerges, consisting of inflowing Atlantic water and outflowing glacially modified water. This exchange transports heat toward the glacier and is primarily balanced by changes in storage and latent heat for melting ice. The total freshwater flux increases over the summer, reaching 1200 ± 700 m3 s−1 of runoff and 1500 ± 500 m3 s−1 of submarine meltwater from glaciers and icebergs in August. The methods and results highlight important components of fjord budgets, particularly the storage and barotropic terms, that have been not been appropriately considered in previous estimates ... |
format |
Article in Journal/Newspaper |
author |
Jackson, Rebecca H. Straneo, Fiamma |
author_facet |
Jackson, Rebecca H. Straneo, Fiamma |
author_sort |
Jackson, Rebecca H. |
title |
Heat, salt, and freshwater budgets for a glacial fjord in Greenland |
title_short |
Heat, salt, and freshwater budgets for a glacial fjord in Greenland |
title_full |
Heat, salt, and freshwater budgets for a glacial fjord in Greenland |
title_fullStr |
Heat, salt, and freshwater budgets for a glacial fjord in Greenland |
title_full_unstemmed |
Heat, salt, and freshwater budgets for a glacial fjord in Greenland |
title_sort |
heat, salt, and freshwater budgets for a glacial fjord in greenland |
publisher |
American Meteorological Society |
publishDate |
2016 |
url |
https://hdl.handle.net/1912/8491 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
glacier Greenland Sermilik |
genre_facet |
glacier Greenland Sermilik |
op_source |
Journal of Physical Oceanography 46 (2016): 2735-2768 doi:10.1175/JPO-D-15-0134.1 |
op_relation |
https://doi.org/10.1175/JPO-D-15-0134.1 Journal of Physical Oceanography 46 (2016): 2735-2768 https://hdl.handle.net/1912/8491 doi:10.1175/JPO-D-15-0134.1 |
op_doi |
https://doi.org/10.1175/JPO-D-15-0134.1 |
container_title |
Journal of Physical Oceanography |
container_volume |
46 |
container_issue |
9 |
container_start_page |
2735 |
op_container_end_page |
2768 |
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1766009487927279616 |