A note on quaternary climate modelling using Boolean delay equations
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The Boolean delay equation model of Ghil et al. for the study of Quaternary ice ages has been re-examined and also extended to include a hydrological feedback mechanism that directly influences the thermohaline circulation. For the basic Ghil et al. model (with the original and with corrected time delays), we show that the maximum duration for a high ice volume state depends continuously but not monotonically on the time delays of the problem. In particular, both short spiky glacials and longer glacials can be obtained from identical parameter values by simply choosing different initial conditions. In the extended model, we find that an additional temperature-hydrology-ocean feedback mechanism tends to generate longer glacials, but in neither case do the average time scales of model variability compare favourably with those of the major Quarternary glacials.
KeywordsTime Delay Equation Model Feedback Mechanism Extended Model Volume State
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- Ghil M, Mulhaupt A (1985) Boolean delay equations. II. Periodic and aperiodic solutions. J Stat Phys 41: 125–173Google Scholar
- Ghil M, Mulhaupt A, Pestiaux P (1987) Deep water formation and Quaternary glaciations. Clim Dyn 2: 1–10Google Scholar
- Kellogg WW (1983) Feedback mechanisms in the climate system affecting future levels of carbon dioxide. J Geophys Res 88: 1263–1269Google Scholar