Структура и динамика полярных токовых систем : материалы международного симпозиума «Полярные геомагнитные явления», 25-31 мая, Суздаль, СССР / Акад. наук СССР, Кол. фил. им. С. М. Кирова, Поляр. геофиз. ин-т. – Апатиты : [б. и.], 1988.

EVENT STUDY. In the following two apeoial events shall be investigated, using EISCAT magnetometer cross data (Pellinen and Nevanlinna 1982). In Pig.5 and 6 the X and Z components of stations PEL, MUO, KAU, ALT and SOR of the EISCAT magnetometer cross are represented for December 10/11, 1983 and May 5/6 1984, correspondingly. In both events a strong positive disturbance in the X component takes place which turns into a negative one after 1800 UT (about 2030 MLT). This is the well-known phenomenon. In both there is dis tinctly to be seen a long periodic variation of the disturbance, represented by the full line. It is interpreted as an influence of large-scale convection and the positive disturbance before 1800 UT as a "convection eastward electro jet" and the negative disturbance after 1800 UT as a consequence of a "convec tion westward electrojet'1 in the sense of Baumjohann (1982) and Kamide and Vickrey (1983). AS it is often being observed and as it had been found already 20 years ago from investigations of equivalent current system, the intensity of the convection eastward electrojet is higher than that of the convection westward electrojet. Distinctly superimposed to this long-periodic variation after 1800 UT occur short-time, intense negative disturbances which can without doubt be recognized as explosive phase of the substorm process; Here it must be asked whether for the hatched areas drawn in Pig.6 after 1200 UT in addition to the convection eastward electrojet occurred intensifications of the eastward electrojet with another structure. Should there be, after all, two different eastward electrojets? In order to investigate this question, calculations of 62