Speaker
Description
It is well established that the total solar irradiance (TSI) varies on
timescales of minute to centuries. On timescales of minutes to hours
the TSI varies due to the globally-averaged superposition of solar
turbulent convection and oscillations, while on solar-cycle and
solar-rotation timescales the majority of the TSI-amplitude
fluctuations are the result of opposing brightenings caused by
faculae/plages and shorter-duration dimmings caused by sunspots. While
TSI variations from minutes to a few decades have been continuously
monitored from space since the late 1970s, TSI variations over much
longer periods of time can only be estimated using either historical
observations of solar surface magnetic features, namely sunspots and
plages, possibly supported by surface flux transport models, or from
the measurements of the cosmogenic isotope (i.e., 14C and 10Be)
concentrations in tree rings and ice cores.
In this work we present a new approach to reconstruct the TSI
variability from the pre-industrial era to the present using component
analysis of time series of historical observations of plages and
sunspots, and the secular trend of the solar potential modulation.
