Freshwater routing in eddy-permitting simulations of the last deglacial: the impact of realistic freshwater discharge
Freshwater, in the form of glacial runoff, is hypothesized to play a critical role in centennial- to millennial-scale climate variability, such as the Younger Dryas and Dansgaard–Oeschger events, but this relationship is not straightforward. Large-scale glacial runoff events, such as Meltwater Pulse...
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2021
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ftdoajarticles:oai:doaj.org/article:4e00e54f74064d58a4ea8ac962fd2df7 2023-05-15T15:16:23+02:00 Freshwater routing in eddy-permitting simulations of the last deglacial: the impact of realistic freshwater discharge R. Love H. J. Andres A. Condron L. Tarasov 2021-11-01T00:00:00Z https://doi.org/10.5194/cp-17-2327-2021 https://doaj.org/article/4e00e54f74064d58a4ea8ac962fd2df7 EN eng Copernicus Publications https://cp.copernicus.org/articles/17/2327/2021/cp-17-2327-2021.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-17-2327-2021 1814-9324 1814-9332 https://doaj.org/article/4e00e54f74064d58a4ea8ac962fd2df7 Climate of the Past, Vol 17, Pp 2327-2341 (2021) Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 article 2021 ftdoajarticles https://doi.org/10.5194/cp-17-2327-2021 2022-12-31T09:06:19Z Freshwater, in the form of glacial runoff, is hypothesized to play a critical role in centennial- to millennial-scale climate variability, such as the Younger Dryas and Dansgaard–Oeschger events, but this relationship is not straightforward. Large-scale glacial runoff events, such as Meltwater Pulse 1a (MWP1a), are not always temporally proximal to subsequent large-scale cooling. Moreover, the typical design of hosing experiments that support this relationship tends to artificially amplify the climate response. This study explores the impact that limitations in the representation of runoff in conventional “hosing” simulations has on our understanding of this relationship by examining where coastally released freshwater is transported when it reaches the ocean. We particularly focus on the impact of (1) the injection of freshwater directly over sites of deep-water formation (DWF) rather than at runoff locations (i.e. hosing), (2) excessive freshwater injection volumes (often by a factor of 5), and (3) the use of present-day (rather than palaeo) ocean gateways. We track the routing of glaciologically constrained freshwater volumes from four different inferred injection locations in a suite of eddy-permitting glacial ocean simulations using the Massachusetts Institute of Technology General Circulation Model (MITgcm) under both open and closed Bering Strait conditions. Restricting freshwater forcing values to realistic ranges results in less spreading of freshwater across the North Atlantic and indicates that the freshwater anomalies over DWF sites depend strongly on the geographical location of meltwater input. In particular, freshwater released into the Gulf of Mexico generates a very weak freshwater signal over DWF regions as a result of entrainment by the turbulent Gulf Stream. In contrast, freshwater released into the Arctic with an open Bering Strait or from the Eurasian ice sheet is found to generate the largest salinity anomalies over DWF regions in the North Atlantic and GIN (Greenland–Iceland–Norwegian) ... Article in Journal/Newspaper Arctic Bering Strait Dansgaard-Oeschger events Greenland Ice Sheet Iceland North Atlantic Directory of Open Access Journals: DOAJ Articles Arctic Bering Strait Greenland Climate of the Past 17 6 2327 2341 |
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Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
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English |
topic |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
spellingShingle |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 R. Love H. J. Andres A. Condron L. Tarasov Freshwater routing in eddy-permitting simulations of the last deglacial: the impact of realistic freshwater discharge |
topic_facet |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
description |
Freshwater, in the form of glacial runoff, is hypothesized to play a critical role in centennial- to millennial-scale climate variability, such as the Younger Dryas and Dansgaard–Oeschger events, but this relationship is not straightforward. Large-scale glacial runoff events, such as Meltwater Pulse 1a (MWP1a), are not always temporally proximal to subsequent large-scale cooling. Moreover, the typical design of hosing experiments that support this relationship tends to artificially amplify the climate response. This study explores the impact that limitations in the representation of runoff in conventional “hosing” simulations has on our understanding of this relationship by examining where coastally released freshwater is transported when it reaches the ocean. We particularly focus on the impact of (1) the injection of freshwater directly over sites of deep-water formation (DWF) rather than at runoff locations (i.e. hosing), (2) excessive freshwater injection volumes (often by a factor of 5), and (3) the use of present-day (rather than palaeo) ocean gateways. We track the routing of glaciologically constrained freshwater volumes from four different inferred injection locations in a suite of eddy-permitting glacial ocean simulations using the Massachusetts Institute of Technology General Circulation Model (MITgcm) under both open and closed Bering Strait conditions. Restricting freshwater forcing values to realistic ranges results in less spreading of freshwater across the North Atlantic and indicates that the freshwater anomalies over DWF sites depend strongly on the geographical location of meltwater input. In particular, freshwater released into the Gulf of Mexico generates a very weak freshwater signal over DWF regions as a result of entrainment by the turbulent Gulf Stream. In contrast, freshwater released into the Arctic with an open Bering Strait or from the Eurasian ice sheet is found to generate the largest salinity anomalies over DWF regions in the North Atlantic and GIN (Greenland–Iceland–Norwegian) ... |
format |
Article in Journal/Newspaper |
author |
R. Love H. J. Andres A. Condron L. Tarasov |
author_facet |
R. Love H. J. Andres A. Condron L. Tarasov |
author_sort |
R. Love |
title |
Freshwater routing in eddy-permitting simulations of the last deglacial: the impact of realistic freshwater discharge |
title_short |
Freshwater routing in eddy-permitting simulations of the last deglacial: the impact of realistic freshwater discharge |
title_full |
Freshwater routing in eddy-permitting simulations of the last deglacial: the impact of realistic freshwater discharge |
title_fullStr |
Freshwater routing in eddy-permitting simulations of the last deglacial: the impact of realistic freshwater discharge |
title_full_unstemmed |
Freshwater routing in eddy-permitting simulations of the last deglacial: the impact of realistic freshwater discharge |
title_sort |
freshwater routing in eddy-permitting simulations of the last deglacial: the impact of realistic freshwater discharge |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/cp-17-2327-2021 https://doaj.org/article/4e00e54f74064d58a4ea8ac962fd2df7 |
geographic |
Arctic Bering Strait Greenland |
geographic_facet |
Arctic Bering Strait Greenland |
genre |
Arctic Bering Strait Dansgaard-Oeschger events Greenland Ice Sheet Iceland North Atlantic |
genre_facet |
Arctic Bering Strait Dansgaard-Oeschger events Greenland Ice Sheet Iceland North Atlantic |
op_source |
Climate of the Past, Vol 17, Pp 2327-2341 (2021) |
op_relation |
https://cp.copernicus.org/articles/17/2327/2021/cp-17-2327-2021.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-17-2327-2021 1814-9324 1814-9332 https://doaj.org/article/4e00e54f74064d58a4ea8ac962fd2df7 |
op_doi |
https://doi.org/10.5194/cp-17-2327-2021 |
container_title |
Climate of the Past |
container_volume |
17 |
container_issue |
6 |
container_start_page |
2327 |
op_container_end_page |
2341 |
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1766346673088364544 |