How northern freshwater input can stabilise thermohaline circulation
The North Atlantic thermohaline circulation (THC) carries heat and salt towards the Arctic. This circulation is partly sustained by buoyancy loss and is generally believed to be inhibited by northern freshwater input as indicated by the ‘box-model’ of Stommel (1961). The inferred freshwater-sensitiv...
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Online Access: | https://hdl.handle.net/1956/16217 https://doi.org/10.3402/tellusa.v68.31051 |
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ftunivbergen:oai:bora.uib.no:1956/16217 2023-05-15T14:50:21+02:00 How northern freshwater input can stabilise thermohaline circulation Lambert, Erwin Eldevik, Tor Haugan, Peter M. 2017-05-10T07:39:59Z application/pdf https://hdl.handle.net/1956/16217 https://doi.org/10.3402/tellusa.v68.31051 eng eng Taylor & Francis On freshwater and the density-driven circulation in the northern seas urn:issn:0280-6495 https://hdl.handle.net/1956/16217 https://doi.org/10.3402/tellusa.v68.31051 cristin:1420295 Attribution CC BY http://creativecommons.org/licenses/by/4.0 Copyright 2016 The Author(s) Tellus. Series A, Dynamic meteorology and oceanography Box-model Arctic Mediterranean freshwater-sensitivity thermohaline circulation Peer reviewed Journal article 2017 ftunivbergen https://doi.org/10.3402/tellusa.v68.31051 2023-03-14T17:39:52Z The North Atlantic thermohaline circulation (THC) carries heat and salt towards the Arctic. This circulation is partly sustained by buoyancy loss and is generally believed to be inhibited by northern freshwater input as indicated by the ‘box-model’ of Stommel (1961). The inferred freshwater-sensitivity of the THC, however, varies considerably between studies, both quantitatively and qualitatively. The northernmost branch of the Atlantic THC, which forms a double estuarine circulation in the Arctic Mediterranean, is one example where both buoyancy loss and buoyancy gain facilitate circulation. We have built on Stommel’s original concept to examine the freshwater-sensitivity of a double estuarine circulation. The net inflow into the double estuary is found to be more sensitive to a change in the distribution of freshwater than to a change in the total freshwater input. A double estuarine circulation is more stable than a single overturning, requiring a larger amount and more localised freshwater input into regions of buoyancy loss to induce a thermohaline ‘collapse’. For the Arctic Mediterranean, these findings imply that the Atlantic inflow may be relatively insensitive to increased freshwater input. Complementing Stommel’s thermal and haline flow regimes, the double estuarine circulation allows for a third: the throughflow regime. In this regime, a THC with warm poleward surface flow can be sustained without production of dense water; a decrease in high-latitude dense water formation does therefore not necessarily affect regional surface conditions as strongly as generally thought. publishedVersion Article in Journal/Newspaper Arctic North Atlantic North atlantic Thermohaline circulation University of Bergen: Bergen Open Research Archive (BORA-UiB) Arctic Tellus A: Dynamic Meteorology and Oceanography 68 1 31051 |
institution |
Open Polar |
collection |
University of Bergen: Bergen Open Research Archive (BORA-UiB) |
op_collection_id |
ftunivbergen |
language |
English |
topic |
Box-model Arctic Mediterranean freshwater-sensitivity thermohaline circulation |
spellingShingle |
Box-model Arctic Mediterranean freshwater-sensitivity thermohaline circulation Lambert, Erwin Eldevik, Tor Haugan, Peter M. How northern freshwater input can stabilise thermohaline circulation |
topic_facet |
Box-model Arctic Mediterranean freshwater-sensitivity thermohaline circulation |
description |
The North Atlantic thermohaline circulation (THC) carries heat and salt towards the Arctic. This circulation is partly sustained by buoyancy loss and is generally believed to be inhibited by northern freshwater input as indicated by the ‘box-model’ of Stommel (1961). The inferred freshwater-sensitivity of the THC, however, varies considerably between studies, both quantitatively and qualitatively. The northernmost branch of the Atlantic THC, which forms a double estuarine circulation in the Arctic Mediterranean, is one example where both buoyancy loss and buoyancy gain facilitate circulation. We have built on Stommel’s original concept to examine the freshwater-sensitivity of a double estuarine circulation. The net inflow into the double estuary is found to be more sensitive to a change in the distribution of freshwater than to a change in the total freshwater input. A double estuarine circulation is more stable than a single overturning, requiring a larger amount and more localised freshwater input into regions of buoyancy loss to induce a thermohaline ‘collapse’. For the Arctic Mediterranean, these findings imply that the Atlantic inflow may be relatively insensitive to increased freshwater input. Complementing Stommel’s thermal and haline flow regimes, the double estuarine circulation allows for a third: the throughflow regime. In this regime, a THC with warm poleward surface flow can be sustained without production of dense water; a decrease in high-latitude dense water formation does therefore not necessarily affect regional surface conditions as strongly as generally thought. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Lambert, Erwin Eldevik, Tor Haugan, Peter M. |
author_facet |
Lambert, Erwin Eldevik, Tor Haugan, Peter M. |
author_sort |
Lambert, Erwin |
title |
How northern freshwater input can stabilise thermohaline circulation |
title_short |
How northern freshwater input can stabilise thermohaline circulation |
title_full |
How northern freshwater input can stabilise thermohaline circulation |
title_fullStr |
How northern freshwater input can stabilise thermohaline circulation |
title_full_unstemmed |
How northern freshwater input can stabilise thermohaline circulation |
title_sort |
how northern freshwater input can stabilise thermohaline circulation |
publisher |
Taylor & Francis |
publishDate |
2017 |
url |
https://hdl.handle.net/1956/16217 https://doi.org/10.3402/tellusa.v68.31051 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic North Atlantic North atlantic Thermohaline circulation |
genre_facet |
Arctic North Atlantic North atlantic Thermohaline circulation |
op_source |
Tellus. Series A, Dynamic meteorology and oceanography |
op_relation |
On freshwater and the density-driven circulation in the northern seas urn:issn:0280-6495 https://hdl.handle.net/1956/16217 https://doi.org/10.3402/tellusa.v68.31051 cristin:1420295 |
op_rights |
Attribution CC BY http://creativecommons.org/licenses/by/4.0 Copyright 2016 The Author(s) |
op_doi |
https://doi.org/10.3402/tellusa.v68.31051 |
container_title |
Tellus A: Dynamic Meteorology and Oceanography |
container_volume |
68 |
container_issue |
1 |
container_start_page |
31051 |
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1766321397245673472 |