End-of-Mission SORCE-SIM Data Release Improvements

Abstract:

The Spectral Irradiance Monitor (SIM) onboard the Solar Radiation and Climate Experiment (SORCE) mission took daily Solar Spectral Irradiance (SSI) measurements from April 2003 – Feb. 2020. We present the end-of-mission data release for SORCE-SIM, describing the calibration methods and improvements, as well as trends measured during Solar cycles 23, 24, and the recent cycle 24-25 solar minimum.

This data release includes significant enhancements to the time and temperature dependencies of the prism and diode degradation corrections, and a spacecraft roll-correction which reduces irradiance outliers. We discuss these, and other improvements, through a comparison of the SSI to previous SORCE data releases, and to SORCE-SOLSTICE and the Total and Spectral Solar Irradiance Sensor (TSIS-1). Finally, we announce a new data product, an absolute flux re-calibration using the latest TSIS data release.