Long-term global climate dynamics: is a stange attractor responsible for the ice ages?
by
Andrei Korobeinikov
Mathematics Departament, University of Auckland
Coauthors: Alex McNabb (University of Auckland)

Rapid and dramatic changes have taken place during the last 2.5 million years of the earth's history. Changes in climate have caused huge ice sheets to expand and contract. Land areas increased far into present sea areas as the global sea level periodically dropped and rose 100m to 150m in response to the growth and melting of glaciers. During the coldest phases (the true ice ages or glacials) the ice sheets expanded over large areas of North America and Europe. During the intermediate warmer phases (the interglacials) the climate and glacier conditions were about the same as they are today. Numerous theories have been proposed to explain these climate and glacier fluctuations. But most of them fail to explain the fairly regular pattern of glacials and interglacials. We will use a simple qualitive model to demonstrate that all all these catastrophic events can be a consequence of the Hoph bifurcation in the system ``ocean---land---atmosphere'', caused by insignificant variations of some parameters (solar radiation in the particular case).

Date received: May 16, 1999

Copyright © 1999 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # cacc-23.