Title: Solar Spectral Reference Spectrum
Author: G. Thuillier
Affil: CNRS
Email: gerard.thuillier@aerov.jussieu.fr
Authors: M. Hersé, P. C. Simon, D. Labs, H. Mandel and D. Gillotay
Affils: IASB, LSW
Abstract: The SOLSPEC instrument has been built to carry out solar spectral irradiance measurements from UV to IR. It flew with the ATLAS and EURECA missions. Data gathered during the three ATLAS missions will be reviewed and compared with results obtained by the sunspectrometers operated at the same time on board the same platforms and on board the UARS satellite. Visible and IR spectra will be presented and compared to existing spectra obtained from ground and from airplanes. Merging the UV, visible and IR data allows to produce a unique spectrum from 200 to 2500 nm. After completing this domain up to 50 microns, the total solar irradiance (TSI) is calculated. It is found to be 1.8 percentage is comparable to the SOLSPEC measurements uncertainties. After, normalization on the observed TSI value by SOLCON, the resulting spectrum is found very close to that of Colina et al. (1996) and the synthetic Kurucz'spectrum.
Title: Ground-Based Irradiance Measurements--Surrogates for Irradiance Models
Author: Stephen Walton
Affil: San Fernando Observatory, Cal State Northridge
Email: stephen.walton@csun.edu
Abstract: I will review the results of modeling of the total solar irradiance (TSI) using ground based images. The various sources of ground based images usable for irradiance modeling will be compared. Techniques will then be discussed for feature identification, proxy computation, and use of those proxies in this modeling. A summary of recent results using these proxies will be presented.
It will be shown that current proxies can reproduce
the observed TSI using a linear regression with
three photometric proxies, representing sunspots, continuum
faculae, and the ultraviolet; these regressions
give an 
value of about 0.9. Non-photometric
proxies such as the Photometric Sunspot Index (PSI)
which are based solely on area can work nearly as well,
and have the advantage that they can be extrapolated
backwards to pre-photometric images.
Remaining uncertainties will be discussed, including but not limited to: Are the bolometric contrasts of solar features well represented by these proxies? Can a more physical model confirm (or eliminate) the possibility that known solar magnetic features account for the observed TSI variability?
Title: Review of Solar Irradiance Models from EUV to IR
Author: P. Fox
Affil: High Altitude Observatory, National Center for Atmospheric Research
Email: pfox@ucar.edu
Abstract: This talk will review the current state of theoretical models of solar spectral irradiance and variability including uncertainties in both the theory, assumptions and inputs (e.g. atomic data). Over the past decade, regular measurement programs for parts of the solar spectrum have been established and the physical understanding of these measurements is rapidly improving. We will discuss several approaches which include combining semi-empirical models and empirical image analysis with the theory for emission, absorption, and transfer of radiation in the solar atmosphere. The ultimate goal is the successful synthesis of observed solar images with line+continuum spectrum emitted from the solar disk.