3. Discussion

[11]  The analysis has shown that the model of external ( K + F ) corona in representation of heliosphere current layer does not adequately describe real distribution of coronal brightness. There is an asymmetry in distribution of coronal brightness up to polar magnetic field reversal and after it. Evidently this is due to the presence of poleward migration of filaments and neutral lines. The coronal condensations exist over the poles forming the bright coronal structures at the distance of 4 R and above. The role of coronal streamers was better showed at low heights about 1.5 R-2.5 R, where ( K + F ) coronal brightness has the branches of migration from high latitude to the equator [Tlatov and Makarov, 2002].

[12]  There is no strongly pronounced longitudinal heterogeneity according to qualitative representation of heliosphere current layer [Bohlin, 1970; Tlatov and Makarov, 2002]. On the other hand, the migration of coronal intensity from high latitudes to the equator after polar magnetic field reversal confirms the model of heliosphere current layer.

[13]  The structure of solar corona reflects the properties of general magnetic field during the global solar cycle. In the minimum activity the streamers are noticeably inclined to the solar equator according to the Atlas of eclipse pictures [Loucif and Koutchmy, 1989; Nesmianovich, 1965] and in the maximum activity the streamers have predominantly radial direction [Koutchmy and Loucif, 1984]. The orientation of coronal streamers depends on the phase of 22-year magnetic cycle [Makarov, 1994]. The most typical peculiarity is the difference in deviation from the radial direction of polar streamers in even and odd cycles. The predominant inclination up to 30^o of high-latitude streamers to the axis of the solar rotation is observed in the maximum of the even 11-year cycle, and predominant radial direction of the streamers is observed at the maximum of the odd 11-year cycle. During the minimum activity, the low-latitude coronal streamers are predominantly inclined equatorward at the angle from 10^o to 25^o.

[14]  The bright streamers turned on a certain angle on clockwise or counterclockwise the day by day according to the series of consecutive images of LASCO-C2. It should be in the case if the streamers are located along bent of heliosphere current layer. This show that the model of huge loops above neutral lines also does not adequately describe distribution of coronal structures [Benevolenskaya et al., 2001]. The polar magnetic field considerably influences on the direction of coronal streamers. There are no essential differences between the nonradial directions of bright or weak coronal streamers. Probably, the deviation of the streamers from radial direction is closely connected with geoeffectiveness of the heliosphere at the magnetic field of the Earth.

[15]  Thus there is actual problem of model formation of solar corona at the heights more than 1.5 R. The model has to describe the sources of corona as from active regions as from neutral lines, and take into account the nonradial direction of the streamers that changes with 22-year magnetic cycle.