Interplanetary magnetic field periodicity of similar to 153 days

We report on the finding of a 153-day periodicity in the magnetic field str ength and solar wind speed measured at 1 AU during the years 1978-1982. The period and the occurence epoch are consistent with the "154-day" periodici ty previously reported for events occurring at the Sun. In particular, the variations in the field strength and the occurence rate of energetic (tens of MeV) solar particle events are in phase. The similar periodicities in th e interplanetary field and solar phenomena are consistent with a global phe nomenon. Whereas this periodicity is quite strong for the magnetic field ma gnitude, there is only a weak periodicity for the individual field componen ts. The field magnitude shows essentially no periodicity at this period dur ing the previous and following solar maxima. The lack of persistence, and o f significant harmonic components of the observed periodicity, does not sup port the proposal of a solar "clock" mechanism. The most significant variat ions in the complete near-earth magnetic field data base (1963-1997) with p eriods of less than 200 days occur at 166 and 146 days.