Magnetic cloud in the solar wind: A comparison with the classical model

The solar wind magnetic field distribution near the Earth has been studied and compared with the distribution anticipated according to the classical model. It has been indicated that a two-hump distribution of the IMF values discovered previously is not an artifact of averaging but reflects the actual structure of the magnetic field within the sector. In this case the magnetic field of polarity corresponding to the leading spot in the Northern Hemisphere is encountered more frequently. Not only the magnetic field magnitude but also the fields of either polarity increase with increasing activity. The distance between the peaks on the histogram of the magnetic field near the Earth increases from 6 to 10 nT. The quasi-22-year, 11-year, and quasibiennial (2.6 ± 0.3 years) cycles are observed in an alternate increase in the peaks, in the strength of the fields of either polarity, and in the ratio of the peaks to the occurrence frequency of zero values, respectively. The classical model is violated in approximately 25% of cases.