HR: 11:15h
AN: SH22B-03 INVITED     [Abstracts]
TI: Non Magnetic Changes in the Total Solar Irradiance
AU: * Dewitte, S
EM: Steven.Dewitte@oma.be
AF: Royal Meteorological Institute of Belgium, Ringlaan 3, Brussels, B-1180 Belgium
AB: From the available total, spectral and spatial observations of solar irradiance, it is known that the major contributions to the irradiance variations on timescales longer than one day come from dark sunspots and bright features on the solar disc. Both the sunspots and the bright features are characterised by an increased magnetic field strength compared to the solar disc background, hence they can be called magnetic features. The current TSI proxy models use the dark sunspots and the bright features as the two 'magnetic' ingredients to reconstruct the measured TSI variation. Accurate measurements with the DIARAD/VIRGO radiometer of the current solar activity cycle show an increase of the TSI at the beginning of the activity cycle which is much stronger than what is predicted by the TSI proxy models. This indicates that an essential 'non magnetic' ingredient is missing in the TSI proxy models. In this presentation we will quantify the missing term from all available TSI measurements.
DE: 7536 Solar activity cycle (2162)
DE: 7538 Solar irradiance
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2005 Joint Assembly