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

• Published in: Nonlinear Processes in Geophysics
• Main Authors: Kwasniok, F., Lohmann, Gerrit
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: COPERNICUS GESELLSCHAFT MBH 2012
• Subjects: Greenland; Greenland ice core; ice core
• Online Access: https://epic.awi.de/id/eprint/31458/; https://epic.awi.de/id/eprint/31458/1/npg-19-595-2012.pdf; http://www.nonlin-processes-geophys.net/19/595/2012/npg-19-595-2012.html; https://hdl.handle.net/10013/epic.40244; https://hdl.handle.net/10013/epic.40244.d001

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.