AMO-like variations of holocene sea surface temperatures in the North Atlantic Ocean

Abstract. Instrumental records of the North Atlantic sea surface temperatures (SST) show a significant 60–80 year cycle, referred to as the Atlantic Multidecadal Oscillation (AMO). During AMO warm (cold) phases, SST over the entire North Atlantic Ocean is dominated by basin-wide positive (negative) anomalies. We analyzed SST variations in the North Atlantic Ocean for the last 10 ka. The long-term and centennial variations of Holocene SST in the North Atlantic demonstrate a basin-wide mode that clearly resembles the AMO signal recorded during the recent instrumental period. The long-term changes of Holocene SST were controlled by the solar insolation related to the orbital variations, and the centennial variations were closely coupled with the intensity of the thermohaline circulation. The spatial extent in the Atlantic realm of temperature anomalies around two specific time intervals, 8.2 ka and during the medieval warm period, also resemble the observed temperature anomalies associated with the AMO. These results demonstrate that the modern AMO, and centennial and longer time scale SST variations during the Holocene share a similar spatial extent in the North Atlantic, and presumably as well physical processes associated with their existence and their far-field teleconnection effects.