A simple conceptual model of abrupt glacial climate events ...

• Main Authors: Braun, Holger, Ganopolski, Andrey, Christl, Marcus, Chialvo, Dante R.
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2007
• Subjects: Dansgaard-Oeschger events; North Atlantic
• Online Access: https://dx.doi.org/10.3929/ethz-b-000008612; http://hdl.handle.net/20.500.11850/8612

Here we use a very simple conceptual model in an attempt to reduce essential parts of the complex nonlinearity of abrupt glacial climate changes (the so-called Dansgaard-Oeschger events) to a few simple principles, namely (i) the existence of two different climate states, (ii) a threshold process and (iii) an overshooting in the stability of the system at the start and the end of the events, which is followed by a millennial-scale relaxation. By comparison with a so-called Earth system model of intermediate complexity (CLIMBER-2), in which the events represent oscillations between two climate states corresponding to two fundamentally different modes of deep-water formation in the North Atlantic, we demonstrate that the conceptual model captures fundamental aspects of the nonlinearity of the events in that model. We use the conceptual model in order to reproduce and reanalyse nonlinear resonance mechanisms that were already suggested in order to explain the characteristic time scale of Dansgaard-Oeschger ... : Nonlinear Processes in Geophysics, 14 (6) ...