HR: 09:05h
AN: SH51E-05 INVITED     [Abstracts]
TI: Physical Origin of the Variations of the Total Solar Irradiance (TSI) on Decadal Timescales or Longer
AU: * Sofia, S
EM: sofia@astro.yale.edu
AF: Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520 United States
AB: A variable (dynamo) magnetic field in the solar interior induces structural changes that result in variations of the global solar parameters (luminosity, radius, and temperature). Of course, as the luminosity changes, so does the basic level of the TSI, which is additionally modulated by surface magnetic activity (spots, faculae, and network). Since the energy reservoir for this internal process is very large, the mechanism can produce TSI modulation over very long timescales, depending only on the properties of the driving magnetic field. In other words, if the dynamo field undergoes secular changes (e.g. Gleissberg cycle or Maunder-type minima), the TSI will also undergo modulation having the same timescales. This paper will describe the current evidence in support of the operation of this mechanism, and how it is currently modeled. In addition, it will describe what observational and theoretical improvements need to be made to produce a model sufficiently robust to explain past change, and to forecast its future effect on climate.
DE: 3359 Radiative processes
DE: 1600 GLOBAL CHANGE (New category)
DE: 1650 Solar variability
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2004 AGU Fall Meeting