Reconstruction of annual solar irradiance

We present the first physics-based reconstruction of total solar irradiance (TSI) at annual resolution over the last three millennia. The reconstruction is obtained by extending the SATIRE-T model beyond the telescopic era using recently published, annually resolved sunspot number series derived from cosmogenic isotope records.

This yields a continuous, physics-based TSI record extending from the satellite era back over the last three millennia, with an annual resolution throughout the pre-telescopic period. Over this full interval, the reconstructed TSI exhibits a maximum difference of 1.04_-0.2_^+0.14^ W/m^2^, defined as the difference between the maximum and minimum of the 50-year running mean values.