In winterthe clockwise current vortex in the dawn sector extends almost over the entire polar cap (except for the periods when the B z component of IMF has a large positive value), and this will result in the positive variation of the Z-value at the geomagnetic pole. From the statistical analysis of the equivalent overhead current patterns for daily geomagnetic variations in the summer and winter polar regions for three different conditions of IMF (interplanetary magnetic field), it was concluded that the annual variation of geomagnetic Z in the vicinity of the geomagnetic pole is attributed to the relative spatial shift of the twin-vortex current patterns over the polar cap from summer to winter. A noticeable depression of the vertical component Z of the geomagnetic field is observed in the polar cap in summer.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |