SOLAR2000 is a collaborative project for accurately characterizing solar ir
radiance variability across the spectrum. A new image- and full-disk proxy
empirical solar irradiance model, SOLAR2000, is being developed that is val
id in the spectral range of 1-1,000,000 nm for historical modeling and fore
casting throughout the solar system. The overarching scientific goal behind
SOLAR2000 is to understand how the Sun varies spectrally and through time
from X-ray through infrared wavelengths. This will contribute to answering
key scientific questions and will aid national programmatic goals related t
o solar irradiance specification. SOLAR2000 is designed to be a fundamental
energy input into planetary atmosphere models, a comparative model with nu
merical/first principles solar models, and a tool to model or predict the s
olar radiation component of the space environment, It is compliant with the
developing International Standards Organization (ISO) solar irradiance sta
ndard. SOLAR2000 captures the essence of historically measured solar irradi
ances and this expands our knowledge about the quiet and variable Sun inclu
ding its historical envelope of variability. The implementation of the SOLA
R2000 is described, including the development of a new EUV proxy, E10.7, wh
ich has the same units as the commonly used F10.7. SOLAR2000 also provides
an operational forecasting and global specification capability for solar ir
radiances and information can be accessed at the website address of http://
www.spacenvironment.net. (C) 2000 Elsevier Science Ltd. All rights reserved
.