Search Publications

Investigation of scaling properties of a thin current sheet by means of particle trajectories study

Sasunov, Yu. L.; Khodachenko, M. L.; Alexeev, I. I. +4 more

A thin current sheet (TCS), with the width of an order of thermal proton gyroradius, appears a fundamental physical object which plays an important role in structuring of major magnetospheric current systems (magnetotail, magnetodisk, etc.). The TCSs are nowadays under extensive study by means of space missions and theoretical models. We consider …

Characteristics of four SPE groups with different origins and acceleration processes

Cho, K. -S.; Kim, R. -S.; Park, Y. -D. +3 more

Solar proton events (SPEs) can be categorized into four groups based on their associations with flare or CME inferred from onset timings as well as acceleration patterns using multienergy observations. In this study, we have investigated whether there are any typical characteristics of associated events and acceleration sites in each group using 4…

Magnetic phase structure of Saturn's 10.7 h oscillations

Dougherty, M. K.; Yates, J. N.; Southwood, D. J.

A source of Saturn's magnetic 10.7 h period oscillations has yet to be identified. The oscillations are known to consist of signals with slightly different periods from separate northern and southern sources. Here we present a novel way of examining observations, focusing on signal phase. We show that although the signals are highly periodic they …

Comment on "Magnetic phase structure of Saturn's 10.7 h oscillations" by Yates et al.

Andrews, D. J.; Cowley, S. W. H.; Provan, G.

Cluster observations of unusually high concentration of energetic O⁺ carried by flux ropes in the nightside high-latitude magnetosheath during a storm initial phase

Dandouras, I.; Reme, H.; Lui, A. T. Y. +6 more

We present measurements from Cluster spacecraft to investigate the energetic singly charged oxygen ions, O⁺, within the flux ropes in the nightside high-latitude magnetosheath during the initial phase of an intense storm on 24 October 2011. Three magnetic flux ropes were identified by Cluster 4 in the intervals from 20:10 UT to 20:20 UT…

Magnetospheric signatures of ionospheric density cavities observed by Cluster

Karlsson, T.; Wright, A. N.; Russell, A. J. B.

We present Cluster measurements of large amplitude electric fields correlated with intense downward field-aligned currents, observed during a nightside crossing of the auroral zone. The data are reproduced by a simple model of magnetosphere-ionosphere coupling which, under different conditions, can also produce a divergent electric field signature…

The use of the power density for identifying reconnection regions

Gunell, H.; Hamrin, M.; Vaivads, A. +2 more

In the vicinity of magnetic reconnection, magnetic energy is transferred into kinetic energy. A reconnection region hence corresponds to a load, and it should manifest itself as large and positive values of the power density, E·J ≫ 0, where E is the electric field and J the current density. In this article we analyze Cluster plasma sheet data from…

Electron density and parallel electric field distribution of the auroral density cavity

Karlsson, T.; Marklund, G. T.; Alm, L.

We present an event study in which Cluster satellites C1 and C3 encounters the flux tube of a stable auroral arc in the premidnight sector. C1 observes the midcavity, while C3 enters the flux tube of the auroral arc at an altitude which is below the acceleration region, before crossing into the top half of the acceleration region. This allows us t…

Dawn-dusk asymmetry in bursty hot electron enhancements in the midtail magnetosheath

Wang, Chih-Ping; Nakamura, T. K. M.; Lyons, Larry R. +1 more

Bursty (a few minutes) enhancements of hot electrons (1-10 keV) in the tail magnetosheath, which we name hot electron enhancements (HEEs), are sometimes observed. To understand the processes leading to HEEs, we have used 4 years of measurements from Acceleration Reconnection Turbulence and Electrodynamics of Moon's Interaction with the Sun mission…

Magnetopause orientation: Comparison between generic residue analysis and BV method

Dorville, Nicolas; Belmont, Gérard; Rezeau, Laurence +2 more

Determining the direction normal to the magnetopause layer is a key step for any study of this boundary. Various techniques have been developed for this purpose. We focus here on generic residue analysis (GRA) methods, which are based on conservation laws, and the new iterative BV method, where B represents the magnetic field and V refers to the i…