Abstract
Abstract. We present the results of a global hybrid code simulation for the solar wind-interaction with the Earth's magnetosphere during an interval of steady radial IMF. The model predicts a foreshock marked by innumerable localized, correlated, and large amplitude, density and magnetic field strength variations, depressed velocities, and enhanced temperatures. The foreshock is bounded by a broad (~0.8 RE) region of enhanced densities, temperatures, and magnetic field strengths that extends far (~8.6 RE) upstream from the bow shock. Flow perturbations within the boundary are directed perpendicular to the boundary, towards the unperturbed solar wind and away from the foreshock. Cluster observations of the ion foreshock and pristine solar wind confirm the predictions of the model. The observations suggest that foreshock cavities, crater-like density and magnetic field strength structures whose cores are filled with suprathermal particles, can be interpreted in terms of transient encounters with the foreshock boundary.
Highlights
The foreshock is the region of space upstream from and magnetically connected to the bow shock that is filled with particles backstreaming from the shock (Eastwood, 2005)
Hot flow anomalies (HFAs) exhibit similar, but far more pronounced, plasma and magnetic field variations, including flows deflected far from the Sun-Earth line (Schwartz et al, 2000). Unlike foreshock cavities, they are centered on interplanetary magnetic field (IMF) discontinuities
This paper presents new results from a two-dimensional self-consistent global hybrid code model for the solar wind-magnetosphere interaction during periods of steady radial IMF orientation and high Mach number
Summary
The foreshock is the region of space upstream from and magnetically connected to the bow shock that is filled with particles backstreaming from the shock (Eastwood, 2005). Hot flow anomalies (HFAs) exhibit similar, but far more pronounced, plasma and magnetic field variations, including flows deflected far from the Sun-Earth line (Schwartz et al, 2000). Unlike foreshock cavities, they are centered on interplanetary magnetic field (IMF) discontinuities. Beam-beam instabilities thermalized the two cold particle distributions, resulting in a single heated population within a cavity bounded by density and magnetic field strength enhancements. Events with foreshock cavity characteristics have not been identified in previously reported self-consistent global hybrid code simulations This paper presents new results from a two-dimensional self-consistent global hybrid code model for the solar wind-magnetosphere interaction during periods of steady radial IMF orientation and high Mach number. Cavities can be interpreted in terms of transient encounters with the boundary of the ion foreshock
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
