This book describes the state-of-the art instruments for measuring the solar irradiance from soft x-ray to the near infrared and the total solar irradiance. Furthermore, the SORCE mission and early results on solar variability are presented along with papers that provide an overview of solar influences on Earth.

"The Solar Radiation and Climate Experiment (SORCE) is a small, free-flying satellite carrying four scientific instruments to measure the solar radiation incident at the top of the Earth's atmosphere. SORCE was successfully launched from NASA's Kennedy Space Center on 25 January 2003. As one element of NASA's Earth Science Enterprise, the SORCE mission is a joint effort between NASA and the Laboratory for Atmospheric and Space Physics (LASP).The primary objectives of SORCE are to make daily measurements of Total Solar Irradiance, TSI, and spectral irradiance over almost the entire spectral range from soft X-rays, through the visible, and into the infrared. The SORCE instruments - the Total Irradiance Monitor (TIM), the Spectral Irradiance Monitor (SIM), two Solar Stellar Irradiance Comparison Experiments (SOLSTICE), and the XUV Photometer System (XPS) - are currently measuring the Sun's total and spectral irradiance with unprecedented accuracy and precision capable of establishing solar variability. In addition to securing a reliable long-term database with which to characterize solar radiative forcing of climate and global change, the SORCE program seeks to foster new understanding of the origins of the solar variations and the physical pathways by which the Earth's atmosphere, oceans, and land respond on multiple time scales.This collection of papers describes the SORCE mission, goals, spacecraft, instrument development and calibration, planning software, ground operations, data processing, early science results, and science implications on how the Sun influences Earth's environment."

The Solar Radiation and Climate Experiment (SORCE) Mission for the NASA Earth Observing System (EOS).- The SORCE Mission.- SORCE Contributions to New Understanding of Global Change and Solar Variability.- An Overview of the Disposition of Solar Radiation in the Lower Atmosphere: Connections to the SORCE Mission and Climate Change.- The SORCE Spacecraft and Operations.- The Total Irradiance Monitor (TIM): Instrument Design.- The Total Irradiance Monitor (TIM): Instrument Calibration.- The Total Irradiance Monitor (TIM): Science Results.- The Spectral Irradiance Monitor: Scientific Requirements, Instrument Design, and Operation Modes.- The Spectral Irradiance Monitor: Measurement Equations and Calibration.- The Spectral Irradiance Monitor (SIM): Early Observations.- Solar-Stellar Irradiance Comparison Experiment II (SOLSTICE II): Instrument Concept and Design.- Solar-Stellar Irradiance Comparison Experiment II (SOLSTICE II): Pre-Launch and On-Orbit Calibrations.- Solar-Stellar Irradiance Comparison Experiment II (SOLSTICE II): Examination of the Solar-Stellar Comparison Technique.- The Mg II Index from SORCE.- XUV Photometer System (XPS): Overview and Calibrations.- XUV Photometer System (XPS): Solar Variations During the SORCE Mission.- The SORCE Science Data System.