Use of cosmogenic radionuclides 14C and 10Be to verify cosmic ray modulation reconstructed since 1616

Abstract

Here we present a new semi-empirical model describing modulation of galactic cosmic rays in the heliosphere. The model is an update of the previous similar model by Alanko-Huotari et al. (2006) and considers such heliospheric parameters as open solar magnetic flux, heliospheric current sheet tilt angle and the large scale solar magnetic field polarity. The model has been tested and calibrated for the period 1976 - 2013 including the very weak solar activity minimum in 2008-2010. Based on this model, and on different reconstructions of the open solar flux, the heliospheric modulation potential is reconstructed since 1610, and subsequently used to compute the production and distribution of cosmogenic radionuclides, such as 10Be and 14C in the terrestrial system. The modelled values are compared with those measured in archives from ice cores and tree rings confirming the validity of our model.