Gnevyshev peaks in solar radio emissions at different frequencies

Abstract

Sunspots have a major 11-year cycle, but the years near the sunspot maximum show two or more peaks called GP (Gnevyshev Peaks). In this communication, it was examined whether these peaks in sunspots are reflected in other parameters such as Lyman-α (the chromospheric emission 121.6 nm), radio emissions 242–15 400 MHz emanating from altitude levels 2000–12 000 km, the low latitude (+45° to −45°) solar open magnetic flux and the coronal green line emission (Fe XIV, 530.3 nm). In the different solar cycles 20–23, the similarity extended at least upto the level of 609 MHz, but in cycle 22, the highest level was of 242 MHz. The extension to the higher level in cycle 22 does not seem to be related to the cycle strength Rz(max), or to the cycle length.