Work

When Simplification Leads to Ambiguity: A Look at Two Ocean Metrics for the Subpolar North Atlantic

Year: 2025

Type: article

Abstract: The AMOC FINGERPRINT and GYRE INDEX are two widely used metrics by the oceanographic community to assess whether northward ocean heat transport, and consequently temperature variability in the subpolar North Atlantic, is primarily governed by the Atlantic overturning circulation or the horizontal gyre circulation. Although these metrics are presented as distinct measures of subpolar ocean circulation, we contend that they are not unique indicators of the dynamics they are intended to represent. Instead, our analysis demonstrates that both metrics are essentially capturing variability in upper ocean heat content, which can result from a number of mechanisms. This conclusion, corroborated with direct overturning measurements from the OSNAP and RAPID programs, raises concerns about the use of these metrics to infer the dynamics responsible for past and projected changes in subpolar ocean temperatures.

Source: Geophysical Research Letters

DOI: 10.1029/2024gl112496

Authors: Léon Chafik, M. Susan Lozier

Institutions: Stockholm University, Bolin Centre for Climate Research, Georgia Institute of Technology

Language: English

Topic: Oceanographic and Atmospheric Processes

Subfield: Oceanography

Field: Earth and Planetary Sciences

Domain: Physical Sciences

SDGs: Life below water, Climate action

Open Access status: gold

Estimated APC paid: $3,190