The so-called modulation potential is a cosmic ray modulation parameter
deduced from space observations of the abundance variation of the different species in function of the solar cycle epoch. It is defined in Nymmik, Panasyuk and Suslov (1996). The energy spectrum of the different primary galactic particles and nuclei can be deduced from the modulation potential. The parameter can be deduced from the sunspot index using a sequence of formulae. A variable delay between solar activity and cosmic ray modulation is used.
Ref. Nymmik R.A., Panasyuk M.I. et Suslov A.A.: 1996, Adv. Space Research, 17, (2)19-(2)30.
The modulation potential is computed from the Ri12 values. Blue bars are deduced from observed Ri12 values and red ones from predicted values. Since a variable delay (mean delay equal 9 months) exists between modulation potential and RI12 values (smoothed over 12 months), predicted values start 3 months after the month when the prediction was made.