An Isaac Newton Institute Workshop

Reconnection in the Sun and Magnetosphere (Hewlett-Packard and Spitalfields Days)

Fractal reconnection at the Earth’s magnetopause and associated ionospheric convection.

Authors: Gary Abel (British Antartic Survey), Iain Coleman (British Antartic Survey), Mervyn Freeman (British Antartic Survey)

Abstract

Large scale properties of reconnection structures on the magnetopause can be explained successfully by simple models incorporating laminar magnetosheath flow with antiparallel reconnection. However, such models are inconsistent with the highly turbulent nature of the magnetosheath flow adjacent to the magnetopause. This presentation proposes a fractal reconnection model that resolves this contradiction by replacing the laminar magnetosheath flow with a turbulent flow which has realistic levels of fluctuation. The resultant fractal reconnection structures preserve the large scale behaviour of simpler models, consistent with ground based observations, but have small scale fluctuations consistent with those observed in situ by spacecraft. We also present observations of evidence for scale-free fluctuations in ionospheric convection associated with dayside reconnection. This scale free behaviour may well arise as a consequence of the fractal reconnection model proposed.