American Geophysical Union Become an AGU Member
Subscribe to AGU Journals		 AGU Home AGU Publications

Subscriber Access to Full Article (Nonsubscribers may purchase for $9.00, Includes print PDF, file size: 709624 bytes)

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 113, A07S14, doi:10.1029/2007JA012776, 2008

The reconnection site of temporal cusp structures

K. J. Trattner

Lockheed-Martin Advanced Technology Center, Palo Alto, California, USA


S. A. Fuselier

Lockheed-Martin Advanced Technology Center, Palo Alto, California, USA


S. M. Petrinec

Lockheed-Martin Advanced Technology Center, Palo Alto, California, USA


T. K. Yeoman

Department of Physics and Astronomy, University of Leicester, Leicester, UK


C. P. Escoubet

European Space Research and Technology Centre, European Space Agency, Noordwijk, Netherlands


H. Reme

Centre d'Etude Spatiale des Rayonnements, UMR 5187, CNRS, Toulouse, France


Abstract

The strong precipitating particle flux in the cusp regions is the consequence of magnetic reconnection between the interplanetary magnetic field and the geomagnetic field. Magnetic reconnection is thought to be the dominant process for mass, energy, and momentum transfer from the magnetosheath into the magnetosphere. Observations of downward precipitating cusp ions by polar orbiting satellites are instrumental in unlocking many questions about magnetic reconnection, e.g., their spatial and temporal nature and the location of the reconnection site at the magnetopause. In this study we combine cusp observations of structures in the precipitating ion-energy dispersion by the Cluster satellites with Super Dual Auroral Radar Network radar observations to distinguish between the temporal and spatial magnetic reconnection processes at the magnetopause. The location of the cusp structures relative to the convection cells is interpreted as a temporal phenomenon caused by a change in the reconnection rate at the magnetopause. The 3-D plasma observations of the Cluster Ion Spectrometry instruments onboard the Cluster spacecraft also provide the means to estimate the location of the reconnection site. While an earlier study of a spatial cusp structure event revealed bifurcated reconnection locations in different hemispheres as origins for the precipitating ions creating the cusp structures, the same method applied to the temporal cusp structures in this study shows only a single tilted reconnection line close to the subsolar point. Tracing the distance to the reconnection site provides not only the location of the reconnection line but can also be used to distinguish between spatial and temporal cusp structures.

Received 27 August 2007; accepted 28 January 2008; published 10 May 2008.

Keywords: cusp; magnetic reconnection; reconnection location.

Index Terms: 2706 Magnetospheric Physics: Cusp; 2712 Magnetospheric Physics: Electric fields (2411); 2723 Magnetospheric Physics: Magnetic reconnection (7526, 7835); 2724 Magnetospheric Physics: Magnetopause and boundary layers; 2784 Magnetospheric Physics: Solar wind/magnetosphere interactions.

Subscriber Access to Full Article (Nonsubscribers may purchase for $9.00, Includes print PDF, file size: 709624 bytes)

Citation: Trattner, K. J., S. A. Fuselier, S. M. Petrinec, T. K. Yeoman, C. P. Escoubet, and H. Reme (2008), The reconnection site of temporal cusp structures, J. Geophys. Res., 113, A07S14, doi:10.1029/2007JA012776.