Mesoscale vortices and associated field- aligned currents observed in the three Iijima - Potemra Regions during substorms
Abstract
During the last decade, different authors carried out a series of works in which there was expanded step by step description of the new system of plasma convection in the polar ionosphere, which arises and develops during substorms and storms. The system is found to consist of a mesoscale vortices. Within each vortex there is concurrent formation of local cell with the maximum density of the field- aligned current (FAC). Clockwise (counterclockwise) vortex always corresponds to the upward (downward) FAC. Simultaneously with one FAC/vortex pair there is formation of adjacent FAC/vortex pair. The direction of the plasma rotation in two adjacent vortex/ PT pairs are opposite as FACs directions. These directions change sign at the transition from R0 to R1 and from R1 to R2. Unlike earlier works, here we describe and analyze the dynamics of the vortex / FAC system covering the whole most active sector (20-02) MLT of the perturbed polar ionosphere and the corresponding region of the geotail, including all three Iijima -Potemra Regions, the boundaries of which are shown on maps of convection and FACs. We discuss the interaction of the vortex / FAC system with BBF. We conclude that BBFs of opposite signs are produced during substorms at the borders R0/R1 and R1/R2.
- Publication:
-
40th COSPAR Scientific Assembly
- Pub Date:
- 2014
- Bibcode:
- 2014cosp...40E2129M