Motivation
Among the many threats posed by global warming, potential changes in the Atlantic meridional overturning circulation (AMOC) and sea-level rise loom large. Reduction in the AMOC’s heat transport could alter hurricane activity, rainfall patterns, and land temperatures, while sea-level rise would cause coastal flooding, loss of wetlands, and beach erosion. What’s more, ocean circulation and sea level are coupled. We must understand how and why AMOC and sea level have changed in the past, and how those changes were related, to project future changes and impacts.
Models project that the AMOC will decline or possibly collapse in the next century, and North Atlantic coastlines will witness enhanced sea-level rise as a result. Yet, it is difficult to determine how realistic these projections are. There is debate about whether AMOC has significantly changed since the Industrial Revolution, because direct AMOC records are short in time and sparse in space. Hence, no authoritative observational benchmark exists for comparing with long-term historical AMOC simulations from models that are also used to project future changes, including of sea level.
We propose to convene a diverse, interdisciplinary Team to use data, modeling, and theory to study the relationship between the AMOC and sea level, and to quantify the value sea-level data add to ocean observing systems. Our proposal is timely given recent advances in space-based observations, data processing algorithms, and the need to find alternatives for expensive in-situ AMOC monitoring arrays. Results may inform historical AMOC reconstructions and projections of impacts from climate change.