Towards two decades of Atlantic Ocean mass and heat transports at 26.5° N

• DOI: 10.1098/rsta.2022.0188
• Publication Date: 2023-10-22T23:05:20Z
• Authors: William E. Johns; Shane Elipot; David A. Smeed; Ben Moat; Brian King; Denis L. Volkov; Ryan H. Smith
• Keywords: climate variability; 13. Climate action; Atlantic meridional overturning circulation; ocean circulation time series; 14. Life underwater; ocean heat transport; Articles

Continuous measurements of the Atlantic meridional overturning circulation (AMOC) and ocean heat transport at 26.5° N began in April 2004 are currently available through December 2020. Approximately 90% total (MHT) is carried by zonally averaged circulation, an even larger fraction variability (approx. 95%) explained overturning. A physically based separation into large-scale AMOC, gyre shallow wind-driven components remains challenging requires new investigations approaches. We review major interannual changes AMOC MHT that have occurred over nearly two decades observations their documented impacts on North content. Changes flow-weighted temperature Florida Current (Gulf Stream) past now taken account estimates MHT, led to increased relative strength recent years. Estimates from coupled models various surface flux datasets still tend show low biases observations, but indirect residual methods (top atmosphere net radiative minus atmospheric energy divergence) shown promise reproducing its variability. This article part a discussion meeting issue ‘Atlantic overturning: challenges’.