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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fttriple:oai:gotriple.eu:bYvn1GB0_-4yvun8EGJyr 2023-05-15T15:14:47+02:00 Freshwater routing in eddy-permitting simulations of the last deglacial: the impact of realistic freshwater discharge Love, Ryan Andres, Heather J. Condron, Alan Tarasov, Lev 2021-11-02 https://doi.org/10.5194/cp-17-2327-2021 https://cp.copernicus.org/articles/17/2327/2021/ en eng doi:10.5194/cp-17-2327-2021 10670/1.oncp4x https://cp.copernicus.org/articles/17/2327/2021/ undefined Geographica Helvetica - geography eISSN: 1814-9332 envir geo Text https://vocabularies.coar-repositories.org/resource_types/c_18cf/ 2021 fttriple https://doi.org/10.5194/cp-17-2327-2021 2023-01-22T17:52:03Z 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) ... Text Arctic Bering Strait Dansgaard-Oeschger events Greenland Ice Sheet Iceland North Atlantic Unknown Arctic Bering Strait Greenland Climate of the Past 17 6 2327 2341 |
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envir geo Love, Ryan Andres, Heather J. Condron, Alan Tarasov, Lev Freshwater routing in eddy-permitting simulations of the last deglacial: the impact of realistic freshwater discharge |
topic_facet |
envir geo |
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 |
Text |
author |
Love, Ryan Andres, Heather J. Condron, Alan Tarasov, Lev |
author_facet |
Love, Ryan Andres, Heather J. Condron, Alan Tarasov, Lev |
author_sort |
Love, Ryan |
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 |
publishDate |
2021 |
url |
https://doi.org/10.5194/cp-17-2327-2021 https://cp.copernicus.org/articles/17/2327/2021/ |
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 |
Geographica Helvetica - geography eISSN: 1814-9332 |
op_relation |
doi:10.5194/cp-17-2327-2021 10670/1.oncp4x https://cp.copernicus.org/articles/17/2327/2021/ |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/cp-17-2327-2021 |
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Climate of the Past |
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17 |
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6 |
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2327 |
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