A simple conceptual model of abrupt glacial climate events

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

2008-03-31

arxiv.org/abs/0803.4429v1

Nonlin. Processes Geophys. 14, 709-721, 2007

Physics

Geophysics

Scientific paper

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) a threshold process, (ii) an overshooting in the stability of the system and (iii) 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 events. In doing so we identify a new form of stochastic resonance (i.e. an overshooting stochastic resonance) and provide the first explicitly reported manifestation of ghost resonance in a geosystem, i.e. of a mechanism which could be relevant for other systems with thresholds and with multiple states of operation. Our work enables us to explicitly simulate realistic probability measures of Dansgaard-Oeschger events (e.g. waiting time distributions, which are a prerequisite for statistical analyses on the regularity of the events by means of Monte-Carlo simulations). We thus think that our study is an important advance in order to develop more adequate methods to test the statistical significance and the origin of the proposed glacial 1470-year climate cycle.

Affiliated with

Also associated with

No associations

Rating

A simple conceptual model of abrupt glacial climate events does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with A simple conceptual model of abrupt glacial climate events, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A simple conceptual model of abrupt glacial climate events will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-197390