IMPACTS OF THE 2002 DROUGHT ON WESTERN RANCHES AND PUBLIC LAND POLICIES

Land Economics/Use,

Chaotic response of global climate to long-term solar forcing variability

It is shown that global climate exhibits chaotic response to solar forcing variability in a vast range of timescales: from annual to multi-millennium. Unlike linear systems, where periodic forcing leads to periodic response, nonlinear chaotic response to periodic forcing can result in exponentially decaying broad-band power spectrum with decay rate T_e equal to the period of the forcing. It is shown that power spectrum of a reconstructed time series of Northern Hemisphere temperature anomaly for the past 2,000 years has an exponentially decaying broad-band part with T_e = 11 yr, i.e. the observed decay rate T_e equals the mean period of the solar activity. It is also shown that power spectrum of a reconstruction of atmospheric CO_2 time fluctuations for the past 650,000 years, has an exponentially decaying broad-band part with T_e = 41,000 years, i.e. the observed decay rate T_e equals the period of the obliquity periodic forcing. A possibility of a chaotic solar forcing of the climate has been also discussed. These results clarify role of solar forcing variability in long-term global climate dynamics (in particular in the unsolved problem of the glaciation cycles) and help in construction of adequate dynamic models of the global climate.Comment: Extended versio

Geological Time Capsule Part III

This is the third part of a three part brief history of the Earth. It covers the Cenozoic Era, which began sixty five million years ago and continues to the present. It is divided into two periods, the Tertiary and Quaternary, comprising seven epochs. The site describes this time interval in terms of plate tectonics, paleoclimatology, and organic evolution. Educational levels: Intermediate elementary, Middle school

Discussion of: A statistical analysis of multiple temperature proxies: Are reconstructions of surface temperatures over the last 1000 years reliable?

Discussion of "A statistical analysis of multiple temperature proxies: Are reconstructions of surface temperatures over the last 1000 years reliable?" by B.B. McShane and A.J. Wyner [arXiv:1104.4002]Comment: Published in at http://dx.doi.org/10.1214/10-AOAS398J the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org