Meridional overturning circulation: stability and ocean feedbacks in a box model

TL;DR

This paper introduces a box model of the Atlantic meridional overturning circulation that examines ocean feedbacks and stability in response to freshwater forcing and perturbations.

Contribution

It develops a novel box model with variable pycnocline depth to analyze stability and feedback mechanisms of the MOC under different freshwater forcing scenarios.

Findings

Feedbacks are sensitive to freshwater perturbations.

Stability depends on the balance of freshwater transport.

Ocean feedbacks influence MOC response to climate variability.

Abstract

A box model of the inter-hemispheric Atlantic meridional overturning circulation is developed, including a variable pycnocline depth for the tropical and subtropical regions. The circulation is forced by winds over a periodic channel in the south and by freshwater forcing at the surface. The model is aimed at investigating the ocean feedbacks related to perturbations in freshwater forcing from the atmosphere, and to changes in freshwater transport in the ocean. These feedbacks are closely connected with the stability properties of the meridional overturning circulation, in particular in response to freshwater perturbations.