The New "Community-Consensus TSI Composite" for Solar and Climate Researchers

Abstract : We present a new total solar irradiance (TSI) composite based on the methodology of Dudok de Wit et al (2017). This new composite has been vetted by the TSI community as that recommended for use by solar and climate researchers. Compared to previously-available composites, which were created by individual principal investigators, this "community-consensus TSI composite" has the advantages of: using a statistically-determined weighting of all available instruments at any time rather than by binarily choosing which instrument data to use at which time; being unbiased in instrument selection by basing weightings on a frequency-dependent noise model from each; having smooth instrument-to-instrument transitions due to time-dependent and scale-wise weightings; and providing time-dependent uncertainties. The composite is scaled to the weighted mean of the contributing instruments with the weightings determined by each instrument's stated uncertainty in absolute value. The composite spans the time range from 1978 to the present and utilizes all but the shortest-duration space-borne TSI instruments during those times covering the spaceflight measurement era. We have computationally implemented this methodology in order to provide solar and climate researchers with regular updates as new data and new instruments become available, such as the recently-launched TSIS/TIM.