Collaborative Research: Prospects and limitations of predicting a potential collapse of the Atlantic meridional overturning circulation

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

This study will address a key aspect of climate change on Earth: the potential collapse of the Atlantic Meridional Overturning Circulation through which the ocean provides heat and moisture to the atmosphere. The study will scrutinize recent propositions that such collapse could occur in the middle of the 21st century. Such challenge will be effected by comparing statistical indices of climate to simplified theoretical models (dynamical systems) and to comprehensive climate models. These models will investigate how stable the current global circulation of the ocean is and whether it can collapse over a few decades. The project will support early-career researchers, one postdoctoral scholar, and one graduate student. It will also seek to reach undergraduate students from economically depressed backgrounds. This study will seek to improve our understanding related to potential collapses of the Atlantic Meridional Overturning Circulation (AMOC). The study will explore limitations of applying Critical Slowing Down (CSD) concepts to AMOC proxies or fingerprints. The framework of CSD indicates that dynamical systems may respond slowly to perturbations as they approach an abrupt transition. Particularly, this study will challenge the recent proposition, obtained with a CSD framework, that the AMOC will collapse in the mid-21st century. Further explorations of this study will delve into the application of dynamical systems in general, and into implementation of methods that go beyond the limitations of CSD to assess stability conditions of the AMOC. The study will attempt to reconcile discrepancies between statistical indicators and results from a) idealized models, and b) comprehensive models. These discrepancies consist of idealized models being able to represent abrupt transitions of AMOC, while comprehensive models seem to be unable to represent such transitions. As Broader Impacts, the project addresses a topic of crucial relevance to climate change understanding. It also will support one graduate student and one postdoctoral scholar, will provide collaborative opportunities to early-career scientists, and will take approximately 100 students from economically depressed backgrounds to a learning camp at the University of North Carolina Wilmington. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.