A simple conceptual model to interpret the 100 000 years dynamics of paleo-climate records

• Published in: Nonlinear Processes in Geophysics
• Main Authors: Quiroga Lombard, C. S., Balenzuela, P., Braun, H., Chialvo, D. R.
• Format: Text
• Language: English
• Published: 2018
• Subjects: Greenland; Greenland Ice Sheet Project; Ice Sheet; North Atlantic
• Online Access: https://doi.org/10.5194/npg-17-585-2010; https://npg.copernicus.org/articles/17/585/2010/

Spectral analyses performed on records of cosmogenic nuclides reveal a group of dominant spectral components during the Holocene period. Only a few of them are related to known solar cycles, i.e., the De Vries/Suess, Gleissberg and Hallstatt cycles. The origin of the others remains uncertain. On the other hand, time series of North Atlantic atmospheric/sea surface temperatures during the last ice age display the existence of repeated large-scale warming events, called Dansgaard-Oeschger (DO) events, spaced around multiples of 1470 years. The De Vries/Suess and Gleissberg cycles with periods close to 1470/7 (~210) and 1470/17 (~86.5) years have been proposed to explain these observations. In this work we found that a conceptual bistable model forced with the De Vries/Suess and Gleissberg cycles plus noise displays a group of dominant frequencies similar to those obtained in the Fourier spectra from paleo-climate during the Holocene. Moreover, we show that simply changing the noise amplitude in the model we obtain similar power spectra to those corresponding to GISP2 δ 18 O (Greenland Ice Sheet Project 2) during the last ice age. These results give a general dynamical framework which allows us to interpret the main characteristic of paleoclimate records from the last 100 000 years.