Joint Seminar: Dependence of the AMOC stability on the background climate

Dependence of the AMOC stability on the background climate

Aixue Hu, Gerald A. Meehl, Ayako Abe-Ouchi, Weiqing Han, Bette Otto-Bliesner, Tongwen Wu, Nan Rosenbloom, Warren G. Strand

The Atlantic conveyor belt circulation is an important global scale oceanic circulation which contributes significantly to the global heat balance. Paleo-proxy records and modeling studies suggest that changes in this circulation may be responsible for the past abrupt climate change events. Here, by using two versions of a coupled climate model, we show that the stability of this circulation depends on the background climate. Under glacial conditions with a closed Bering Strait, a sudden collapse of this circulation is possible and induces an abrupt climate change events in the North Atlantic and surrounding regions. However, under present day condition with an open Bering Strait, this circulation could collapse suddenly due to either thermal or haline forcings without causing abrupt climate change events. Our result is important to understand the paradox regarding frequent occurrence of the abrupt climate change event during glacial time, but nearly none during the Holocene. 

Date

26.07.2016

Time

15:15 h

Place

Bundesstr. 53, room 022/023
Seminar Room 022/023, Ground Floor, Bundesstrasse 53, 20146 Hamburg, Hamburg

Speaker

Aixue Hu, Global Climate Dynamics Division (CGD), National Center for Atmospheric Research (NCAR), Boulder, CO, USA

Organizers

Chao Li

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