Long Long-term variations of solar, interplanetary and geomagnetic indices

摘要

The long long-term variations of the 12 12-month running means of several solar, interplanetary and geomagnetic parameters dur during the last several sunspot cycles revealed that the sunspot numbers Rz showed smooth but broad maxima for 3 years in each ing cycle, the geomagnetic aa index showed several peaks within 5 years around the sunspot maxima, with some peaks during the dec decli lin- ning ing phases of the sunspot cycles. The 11 11-year running means showed very good correlation between Rz, aa index and global sea surface temperature (SST). Rz and F10 (2800 MHz radio emission) showed similar 11 11-year fluctuations of varying amplitudes, but coronal index CI showed monotonically increasing amplitudes by almost a factor of two. The open magnetic flux emanating from the Sun showed long long-term fluctuations very different at low and high solar latitudes. The variations of the fluxes at low latitude (0 0-45o) were almost parallel to the sunspot cycle (there was a slight N N-S asymmetry), while fluxes at high latitudes (45o 45o-90o) were almost anti anti-parallel to the sunspot cycle. Cosmic ray neutron monitor intensities at two different neutron monitoring stations were well anti anti- correlated with sunspot cycle and interplanetary magnetic field B but poorly correlated with interplanetary number density N, solar wind speed V, and geomagnetic index aa. The geomagnetic index aa was best correlated with the product VB.