HR: 13:40h
AN: U23A-01    [Abstracts]
TI: Modelling Climate of the Last Million Years
AU: * Berger, A L
EM: berger@astr.ucl.ac.be
AF: Universit‚ catholique de Louvain, Institut d'Astronomie et de Geophysique G. Lemaitre, Chemin du Cyclotron, 2, Louvain-la-Neuve, 1348 Belgium
AU: Melice, J
EM: JMELICE@ocean.uct.ac.za
AF: University of Cape Town, Dept. of Oceanography, Rondebosch, RONDEBOSCH, 7701 South Africa
AU: Loutre, M
EM: loutre@astr.ucl.ac.be
AF: Universit‚ catholique de Louvain, Institut d'Astronomie et de Geophysique G. Lemaitre, Chemin du Cyclotron, 2, Louvain-la-Neuve, 1348 Belgium
AB: Around 1 Myr BP, the power of the 100-kyr period in eccentricity starts to decrease progressively for the benefits of the 400-kyr period which dominates up to now and mainly over the next 400 kyr. This eccentricity cycle fades away at the same time that the 100-kyr cycle appears stronger and stronger in climate records. This underlines the importance of non-linear feedback mechanisms which are necessary to create the 100-kyr climate signal. It shows also that a direct response to eccentricity can not be invocated. Modeling experiments using the LLN (Louvain-la-Neuve) climate model of intermediate complexity forced with daily insolation for each latitude shows spectral features which are pretty similar to those found in proxy records. Spectral characteristics of the simulated annual mean temperature and ice volume are broadly the same, but the signal in the 100-kyr band is much weaker in temperature than in ice volume.
DE: 3344 Paleoclimatology
DE: 4267 Paleoceanography
DE: 1600 GLOBAL CHANGE (New category)
SC: Union [U]
MN: 2004 AGU Fall Meeting