Abstract
Abstract. We present magnetic field and particle data recorded by the Cluster and Geotail satellites in the vicinity of the high- and low-latitude dayside magnetopause, respectively, on 17 February 2003. A favourable conjunction of these spacecraft culminated in the observation of a series of flux transfer events (FTEs), characterised by bipolar perturbations in the component of the magnetic field normal to the magnetopause, an enhancement in the overall magnetic field strength, and field tilting effects in the plane of the magnetopause whilst the satellites were located on the magnetosheath side of the boundary. Whilst a subset of the FTE signatures observed could be identified as being either normal or reverse polarity, the rapid succession of events observed made it difficult to classify some of the signatures unambiguously. Nevertheless, by considering the source region and motion of flux tubes opened by magnetic reconnection at low latitudes (i.e. between Cluster and Geotail), we demonstrate that the observations are consistent with the motion of northward (southward) and tailward moving flux tubes anchored in the Northern (Southern) Hemisphere passing in close proximity to the Cluster (Geotail) satellites. We are able to demonstrate that a multi-spacecraft approach, coupled with a realistic model of flux tube motion in the magnetosheath, enables us to infer the approximate position of the reconnection site, which in this case was located at near-equatorial latitudes.
Highlights
Magnetic reconnection is the predominant mechanism by which solar wind energy and momentum are transmitted into the terrestrial magnetospheric cavity
The flux transfer events (FTEs) signatures observed by Cluster and Geotail were principally characterised by bipolar perturbations in the magnetic field component in the direction normal to the magnetopause and enhancements in the overall magnetic field strength
The predicted northward evolution of reconnected flux tubes anchored in the Northern Hemisphere resulted in them passing over the locations of the Cluster satellites, and was entirely consistent with the observation of normal polarity FTE signatures by each spacecraft
Summary
Magnetic reconnection is the predominant mechanism by which solar wind energy and momentum are transmitted into the terrestrial magnetospheric cavity. A. Wild et al.: Cluster and Geotail observations of FTEs using high-latitude magnetic field data from the ISEE spacecraft, reported observations of bipolar perturbations that were directed first in the outward normal and the inward normal direction (i.e. in the positive negative normal direction), Rijnbeek et al (1982) presented observations of FTEs at equatorial latitudes that were characterised by inward outward (negative-positive) bipolar signatures. Wild et al.: Cluster and Geotail observations of FTEs using high-latitude magnetic field data from the ISEE spacecraft, reported observations of bipolar perturbations that were directed first in the outward normal and the inward normal direction (i.e. in the positive negative normal direction), Rijnbeek et al (1982) presented observations of FTEs at equatorial latitudes that were characterised by inward outward (negative-positive) bipolar signatures These signatures, referred to as “normal” and “reverse” polarity FTEs, were interpreted as encounters with newly-opened flux tubes connected to the northern and Southern Hemispheres, respectively.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have