Uncertainty propagation in global radionuclide production rate estimates to constrain solar particle event intensity

Radionuclides, like ¹⁴C and ¹⁰Be, are produced by interactions of the Earth's atmosphere with high energetic particles from space. The discovery of large peaks in ¹⁴C and ¹⁰Be concentration has been linked to severe solar particle events (SPEs), that occured in the past millenia. Besides solar activity, the production rates of radionuclides also depend on the Earth's magnetic field, which shields the planet against cosmic radiation. To infer the strength of the SPE, the amount of shielding has to be known. Here we investigate how uncertainties in the reconstruction of the global geomagnetic field propagate to ¹⁰Be production rates. We make use of recent ensemble models for the Holocene geomagnetic field, combined with particle tracing codes, to provide locally resolved cutoff rigidities and ¹⁰Be production rates, together with the associated uncertainties. These can be used in combination with deposition models, to estimate ¹⁰Be depositional flux. The estimates can be compared to measurements, in order to determine upper and lower bounds for the SPE strength.