for the CMIP6 solar forcing team:

K. Matthes, B Funke, M. E. Andersson, L. Barnard, J. Beer, P. Charbonneau, M. A. Clilverd, T. Dudok de Wit, M. Haberreiter, A. Hendry , C. H. Jackman, M. Kretzschmar, T. Kruschke, M. Kunze, U. Langematz, D. R. Marsh, A. Maycock, S. Misios, C. J. Rodger, A. A. Scaife, A. Seppälä, M. Shangguan, M. Sinnhuber, K. Tourpali, I. Usoskin,  M. van de Kamp, P. T. Verronen, and S. Versick

We describe the recently generated solar forcing dataset for CMIP6 and highlight in particular changes with respect to the CMIP5 recommendation. The solar forcing is provided for radiative properties, i.e., total solar irradiance (TSI) and solar spectral irradiance (SSI), and F10.7cm radio flux, as well as particle forcing, i.e., geomagnetic indices Ap and Kp, and ionisation rates to account for effects of solar protons, electrons and galactic cosmic rays. This is the first time that a recommendation for solar-driven particle forcing is provided for a CMIP exercise. The solar forcing dataset is provided at daily and monthly resolution separately for the CMIP6 Historical Simulation (1850–2014), for the future (2015–2300), including an additional extreme Maunder Minimum-like sensitivity scenario, as well as for a constant and a time-varying forcing for the preindustrial control simulation. This paper provides an overview on the forcing dataset and how it was created, and discusses implications for climate modeling.