Recurrency and the origin of the vertical component of the interplanetary magnetic field

The autocorrelation functions of the solar wind velocity and of the IMF components as well as of the geomagnetic activity indices are studied for two periods: August–December, 1965 and January–May, 1974. The vertical component of the IMF is shown to exhibit a rather definite recurrency relatively independent of the recurrency of the solar wind velocity.The daily mean values of the Z-component of the IMF are shown to correlate ( = -0.5) with the intensity of the meridional component of the large scale solar magnetic field with time delay of about 5 days with respect to the latter. This result is interpreted as an evidence for the Z- component of the IMF to be carried away by the solar wind from the Sun.     

Reconstruction of the sector structure of the interplanetary magnetic field by geomagnetic station data

This paper describes a new method for reconstructing the polarity of the interplanetary magnetic field. The technique is based on the Svalgaard-Mansurov effect. We ause geomagnetic data of high-latitude stations with a long observation period, including the presatellite era. This method is designed to improve the quality and accuracy of reconstructed polarity, complementing the results of previous methods of Svalgaard (1975) and Vennerstr?m et al. (2001). For the large presatellite period from 1926, the accuracy of the method is estimated to be around 89% of overlaps with the interplanetary magnetic field polarity determined from satellite data.