Title:  Sunshine, Earthshine and Climate

Phil Goode 
New Jersey Institute of Technology, and 
Director, Big Bear Solar Observatory


Abstract:
 
The earth's climate depends on the sun's radiative output and the earth's
reflectance.  Variations in the sun's radiative output  have been
carefully measured from  space for more the twenty years.  The sun's
irradiance is about 0.1% greater at activity maximum.  Recent information
from the  helioseismic detectors aboard SoHO have shed light on the
physical origin  of the evolution revealing that the sun may be cooler
when its radiative  output is greatest.  The results also imply sharp
limits on the variation  of the solar output.  

The earthshine has been measured for several years from Big Bear Solar 
Observatory to determine the earth's large scale reflectance.  The earth's 
reflectance is not so well studied as the sun's irradiance, but it does 
seem to be much more highly variable.   The earth's varying albedo is 
largely a story of clouds.  Secular, seasonal, annual and solar cycle 
dependences of the earth's reflectivity will be compared to those from our 
simulations of the reflectance.