The Atlantic Multi-Decadal Oscillation

This paper reviews the history of research on the Atlantic Multi-decadal Oscillation (AMO), including its dynamics, global teleconnections, global impacts, and connection to global mean surface temperature. The AMO is a global-scale coupled ocean-atmosphere oscillation of the climate system with significant sea surface temperature (SST) anomalies in all ocean basins. It is associated with significant oscillation of the Atlantic Meridional Overturning Circulation (AMOC), which is likely driven by tidal gravitational forcing through tidal mixing and enhanced by volcano forcing and cloud-radiation feedback. The AMO strongly affects surface air temperature (T-air) and Palmer Drought Severity Index (PDSI) over all the continents. The phase lag varies among different continents. Over the tropical continents, T-air and PDSI tend to be in phase with each other. Over the extratropical continents, T-air and PDSI tend to be out of phase with each other. The AMO contributes significantly to global mean surface temperature and global warming hiatus.