Simulated Atlantic Multidecadal Oscillation during the Holocene

• Published in: Journal of Climate
• Main Authors: Wei, Wei, Lohmann, Gerrit
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: AMER METEOROLOGICAL SOC 2012
• Subjects: Ice Sheet; North Atlantic; Sea ice
• Online Access: https://epic.awi.de/id/eprint/30360/; http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-11-00667.1; https://hdl.handle.net/10013/epic.39294

The Atlantic Multidecadal Oscillation (AMO) and its possible change during the Holocene are examined in this study, using long-term simulations of the Earth system model COSMOS. A quasi-persistent ~55- to 80-year cycle characterizing in the North Atlantic sea surface temperature, is highly associated with the multidecadal variability of the Atlantic Meridional Overturning Circulation (AMOC) during the Holocene. This mode can be found throughout the Holocene, indicating that the AMO is dominated by internal climate variability. Stronger-than-normal AMOC results in warmer-than-normal surface temperature, spreading over almost the whole North Hemisphere, in particular the North Atlantic Ocean. During the warm phase of the AMO, more precipitation is detected in the North Atlantic low and high latitudes. It also generates a dipolar seesaw pattern in the sea ice anomaly. The results reveal that the influence of the AMO can be amplified by a more vigorous AMOC variability during the early Holocene in the presence of a remnant of the Laurentide Ice Sheet and when freshwater entered the North Atlantic Ocean. This conclusion could have potential application for the past AMO reconstruction and the future AMO estimation.