Articles | Volume 19, issue 6
Nonlin. Processes Geophys., 19, 595–603, 2012
https://doi.org/10.5194/npg-19-595-2012

Special issue: Recent advances in data analysis and modeling of nonlinear...

Nonlin. Processes Geophys., 19, 595–603, 2012
https://doi.org/10.5194/npg-19-595-2012

Research article 07 Nov 2012

Research article | 07 Nov 2012

A stochastic nonlinear oscillator model for glacial millennial-scale climate transitions derived from ice-core data

F. Kwasniok1 and G. Lohmann2 F. Kwasniok and G. Lohmann
  • 1College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK
  • 2Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany

Abstract. A stochastic Duffing-type oscillator model, i.e noise-driven motion with inertia in a potential landscape, is considered for glacial millennial-scale climate transitions. The potential and noise parameters are estimated from a Greenland ice-core record using a nonlinear Kalman filter. For the period from 60 to 20 ky before present, a bistable potential with a deep well corresponding to a cold stadial state and a shallow well corresponding to a warm interstadial state is found. The system is in the strongly dissipative regime and can be very well approximated by an effective one-dimensional Langevin equation.