The study of the robust features of the magnetosphere is motivated both by new "whole system" approaches, and by the idea of "space climate" as opposed to "space weather". We enumerate these features for the AE index, and discuss whether self-organised criticality (SOC) is the most natural explanation of the "stylised facts" so far known for AE. We identify and discuss some open questions, answers to which will clarify the extent to which AE's properties provide evidence for SOC. We then suggest an SOC-like reconnection-based scenario drawing on the result of Craig(2001) as an explanation of the very recent demonstration by Uritsky et al(2001b) of power laws in several properties of spatiotemporal features seen in auroral images.
- Pub Date:
- April 2002
- 24 pages including 7 figures. Based on an invited talk given at the IAGA meeting in Hanoi, Vietnam, August 2000. Retitled v2 has revisions, clearer statement of intent of paper i.e. part review/part critique/some new suggestions, and 1 new figure. In press, Nonlinear Processes in Geophysics