M.: Precise calculations of the existence of multiple AMOC equilibria in coupled climate models Part I: equilibrium states
This study examines criteria for the existence of two stable states of the Atlantic Meridional Overturning Circulation (AMOC) using a combination of theory and simulations from a numerical coupled atmosphere– ocean climate model. By formulating a simple collection of state parameters and their relat...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.682.7227 2023-05-15T13:47:55+02:00 M.: Precise calculations of the existence of multiple AMOC equilibria in coupled climate models Part I: equilibrium states Willem P. Sijp Matthew H. England Jonathan M. Gregory The Pennsylvania State University CiteSeerX Archives application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.682.7227 http://web.science.unsw.edu.au/%7Ematthew/AMOC_BISTABILITY_PartI.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.682.7227 http://web.science.unsw.edu.au/%7Ematthew/AMOC_BISTABILITY_PartI.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://web.science.unsw.edu.au/%7Ematthew/AMOC_BISTABILITY_PartI.pdf text ftciteseerx 2016-01-08T17:58:27Z This study examines criteria for the existence of two stable states of the Atlantic Meridional Overturning Circulation (AMOC) using a combination of theory and simulations from a numerical coupled atmosphere– ocean climate model. By formulating a simple collection of state parameters and their relationships, the authors reconstruct the North Atlantic Deep Water (NADW) OFF state behavior under a varying external salt-flux forcing. This part (Part I) of the paper examines the steady-state solution,which gives insight into themechanisms that sustain the NADWOFF state in this coupled model; Part II deals with the transient behavior predicted by the evolution equation. The nonlinear behavior of the Antarctic Intermediate Water (AAIW) reverse cell is critical to the OFF state. Higher Atlantic salinity leads both to a reduced AAIW reverse cell and to a greater vertical salinity gradient in the South Atlantic. The former tends to reduce Atlantic salt export to the Southern Ocean, while the latter tends to increases it. These competing effects produce a nonlinear response of Atlantic salinity and salt export to salt forcing, and the existence of maxima in these quantities. Thus the authors obtain a natural and accurate analytical saddle-node condition for the maximal surface salt flux for which a NADW OFF state exists. By contrast, the bistability indicator proposed byDeVries andWeber does not generally work in this model. It is applicable only when the effect of the AAIW reverse cell on the Atlantic salt budget is weak. 1. Text Antarc* Antarctic NADW North Atlantic Deep Water North Atlantic Southern Ocean Unknown Antarctic Southern Ocean The Antarctic |
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English |
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This study examines criteria for the existence of two stable states of the Atlantic Meridional Overturning Circulation (AMOC) using a combination of theory and simulations from a numerical coupled atmosphere– ocean climate model. By formulating a simple collection of state parameters and their relationships, the authors reconstruct the North Atlantic Deep Water (NADW) OFF state behavior under a varying external salt-flux forcing. This part (Part I) of the paper examines the steady-state solution,which gives insight into themechanisms that sustain the NADWOFF state in this coupled model; Part II deals with the transient behavior predicted by the evolution equation. The nonlinear behavior of the Antarctic Intermediate Water (AAIW) reverse cell is critical to the OFF state. Higher Atlantic salinity leads both to a reduced AAIW reverse cell and to a greater vertical salinity gradient in the South Atlantic. The former tends to reduce Atlantic salt export to the Southern Ocean, while the latter tends to increases it. These competing effects produce a nonlinear response of Atlantic salinity and salt export to salt forcing, and the existence of maxima in these quantities. Thus the authors obtain a natural and accurate analytical saddle-node condition for the maximal surface salt flux for which a NADW OFF state exists. By contrast, the bistability indicator proposed byDeVries andWeber does not generally work in this model. It is applicable only when the effect of the AAIW reverse cell on the Atlantic salt budget is weak. 1. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Willem P. Sijp Matthew H. England Jonathan M. Gregory |
spellingShingle |
Willem P. Sijp Matthew H. England Jonathan M. Gregory M.: Precise calculations of the existence of multiple AMOC equilibria in coupled climate models Part I: equilibrium states |
author_facet |
Willem P. Sijp Matthew H. England Jonathan M. Gregory |
author_sort |
Willem P. Sijp |
title |
M.: Precise calculations of the existence of multiple AMOC equilibria in coupled climate models Part I: equilibrium states |
title_short |
M.: Precise calculations of the existence of multiple AMOC equilibria in coupled climate models Part I: equilibrium states |
title_full |
M.: Precise calculations of the existence of multiple AMOC equilibria in coupled climate models Part I: equilibrium states |
title_fullStr |
M.: Precise calculations of the existence of multiple AMOC equilibria in coupled climate models Part I: equilibrium states |
title_full_unstemmed |
M.: Precise calculations of the existence of multiple AMOC equilibria in coupled climate models Part I: equilibrium states |
title_sort |
m.: precise calculations of the existence of multiple amoc equilibria in coupled climate models part i: equilibrium states |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.682.7227 http://web.science.unsw.edu.au/%7Ematthew/AMOC_BISTABILITY_PartI.pdf |
geographic |
Antarctic Southern Ocean The Antarctic |
geographic_facet |
Antarctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic NADW North Atlantic Deep Water North Atlantic Southern Ocean |
genre_facet |
Antarc* Antarctic NADW North Atlantic Deep Water North Atlantic Southern Ocean |
op_source |
http://web.science.unsw.edu.au/%7Ematthew/AMOC_BISTABILITY_PartI.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.682.7227 http://web.science.unsw.edu.au/%7Ematthew/AMOC_BISTABILITY_PartI.pdf |
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Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
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1766248014927626240 |