Since January 1996, the SOHO/VIRGO experiment has been observing the total (spectrally integrated) solar irradiance with the DIARAD and PMO6-V instruments, as well as the solar spectral irradiance in three channels - in the near-UV at 402 nm, in the visible at 500 nm, and in the infrared at 862 nm - with the SPM instrument. The VIRGO total and spectral irradiance measurements have revealed variations related to the appearance of active regions on time scales of days to weeks. Both the DIARAD and PMO6-V total irradiance data show that the total solar irradiance started to increase in late October, 1996, similar to the behavior of the Mg II index (core-to-wing ratio) derived from the UV irradiance observations of the SUSIM instrument on the Upper Atmosphere Research Satellite (UARS). The main goal of this paper is to compare the VIRGO total and spectral irradiance as well as the UARS/SUSIM UV irradiance with the magnetic plage and sunspot indices derived from the observations of the 525 nm line at the Mt. Wilson Observatory.
AAS/Solar Physics Division Meeting #28
- Pub Date:
- May 1997