Disentangling North Atlantic ocean-atmosphere coupling using circulation analogues ...

The coupled nature of the ocean-atmosphere system frequently makes understanding the direction of causality difficult in ocean-atmosphere interactions. This study presents a method to decompose turbulent heat fluxes into a component which is directly forced by atmospheric circulation, and a residual...

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Bibliographic Details
Main Authors: Patterson, Matthew, O'Reilly, Christopher, Robson, Jon, Woollings, Tim
Format: Article in Journal/Newspaper
Language:unknown
Published: arXiv 2023
Subjects:
Online Access:https://dx.doi.org/10.48550/arxiv.2310.10446
https://arxiv.org/abs/2310.10446
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Summary:The coupled nature of the ocean-atmosphere system frequently makes understanding the direction of causality difficult in ocean-atmosphere interactions. This study presents a method to decompose turbulent heat fluxes into a component which is directly forced by atmospheric circulation, and a residual which is assumed to be primarily `ocean-forced'. This method is applied to the North Atlantic in a 500-year pre-industrial control run using the Met Office's HadGEM3-GC3.1-MM model. The method identifies residual heat flux modes largely associated with variations in ocean circulation and shows that these force equivalent barotropic circulation anomalies in the atmosphere. The first of these modes is characterised by the ocean warming the atmosphere along the Gulf Stream and North Atlantic Current and the second by a dipole of cooling in the western subtropical North Atantic and warming in the sub-polar North Atlantic. Analysis of atmosphere-only simulations confirms that these heat flux patterns are indeed ... : 44 pages, 17 figures ...