Neutron monitors and muon detectors for solar modulation studies: 2. $\phi$ time series

Understand

The level of solar modulation at different times (related to the solar activity) is a central question of solar and galactic cosmic-ray physics.

• In the first paper of this series, we have established a correspondence between the uncertainties on ground-based detectors count rates and the parameter $\phi$ (modulation level in the force-field approximation) reconstructed from these count rates.
• In this second paper, we detail a procedure to obtain a reference $\phi$ time series from neutron monitor data.
• We show that we can have an unbiased and accurate $\phi$ reconstruction ($\Delta\phi/\phi\simeq 10\%$).