Short- and Mid-term Periodicities Observed in Neutron Monitor Counting Rates throughout Solar Cycles 20–24

Abstract This paper examines the short- and mid-term periodicities (≲2 yr) in cosmic-ray flux along 55 yr, from 1964 to 2019. The has been computed by averaging counting rates, typified units, of a set selected neutron monitors. builds representative virtual monitor, named global monitor. relevant discovered are ∼13.5, ∼27, ∼46–64, ∼79–83 day; Rieger-type (∼134–190 days); ∼225–309 ∼1.06–1.15, ∼1.31–1.40, ∼1.75–2.20 yr periods. same analyses have applied sunspot number (SSN) with aim compare look for possible origins these periodicities. Two main results achieved: 77–83 days, 134–190 days (Rieger type), 225–309 ∼1.3 ∼1.7 could be related solar dynamo, an inversely linear relationship found between average SSN versus duration time each cycle period.