On The Inferred Secular Variation of the Heliospheric Magnetic Field

Abstract

Abstract: There is a considerable interest in the long term influence of solar activity on terrestrial climate. Earlier work, by using correlation between geomagnetic aa index and galactic cosmic ray counts, inferred that the radial component of the interplanetary magnetic field at 1 A.U. increases secularly. However, our results show that there is no correlation between geomagnetic aa index and galactic cosmic ray counts. Averaging has to be very carefully dealt with the aa index and other parameters that depend upon sign of interplanetary magnetic field as average value and most probable value may not coincide.