154 day solar periodicity

spaceweb@oulu.fi - last update: 22 December 1998, 2020 UT (RR)

The 154 day periodicity in the Sun was first reported on gamma-ray flares (Rieger et al., 1984). Later the same periodicity has been found in many other paremeters related to Sun and solar wind/IMF, although it does not seem to be a persistent periodicity, and the exact period varies between 140 and 170 days. For example, Cane et al. (1998) found a 153 day periodicity in IMF strength for solar maximum years 1978-1982, but not for the preceeding or subsequent solar cycles.

Variables showing ~154 day periodicity
Variable Reference
Flare related Rieger et al., 1984; Bai and Cliver, 1990; Bai and Sturrock, 1993
Active region parameters (sunspot areas etc.) Lean and Brueckner, 1989; Lean, 1990
F10.7 Lean and Brueckner, 1989
IMF strength and solar wind velocity Cane et al., 1998


See also