AGU SH21B 12/10/02 Richard C. Willson - Columbia University 1 ACRIM INSTRUMENT TEAM Roger S. Helizon, Jet Propulsion Laboratory Instrument Scientist roger@simdac.jpl.nasa.gov Variations of Total Solar Irradiance during solar cycles 21-23: Measurements and Models Richard C. Willson & Alex V. Mordvinov ACRIM SCIENCE TEAM Dr. Richard C. Willson, Columbia University Principal Investigator acrim@acrim.com Dr. Alex Mordvinov, Head –Solar Activity Laboratory Institute Of Solar Terrestrial Physics, Irkutsk, Russia Co-Investigator Dr. James Hansen, Director – NASA/GISS Co-Investigator Dr. Hugh S. Hudson – University of CA at Berkeley Co-Investigator