Search Publications
A magnetic reconnection X-line extending more than 390 Earth radii in the solar wind
Balogh, A.; McComas, D. J.; Reme, H. +8 more
Magnetic reconnection in a current sheet converts magnetic energy into particle energy, a process that is important in many laboratory, space and astrophysical contexts. It is not known at present whether reconnection is fundamentally a process that can occur over an extended region in space or whether it is patchy and unpredictable in nature. Fre…
Local structure of the magnetotail current sheet: 2001 Cluster observations
Sauvaud, J. -A.; Balogh, A.; Zhang, T. L. +10 more
Thirty rapid crossings of the magnetotail current sheet by the Cluster spacecraft during July-October 2001 at a geocentric distance of 19 RE are examined in detail to address the structure of the current sheet. We use four-point magnetic field measurements to estimate electric current density; the current sheet spatial scale is estimate…
Joint observations by Cluster satellites of bursty bulk flows in the magnetotail
Zhang, T. L.; Dandouras, I.; Lucek, E. +9 more
Using the observations of three satellites of Cluster (C1, C3, and C4) during the periods July to October 2001 and July to October 2002, we study 209 active time bursty bulk flows (BBFs), the difference between single satellite observations and multisatellite observations, and the difference among three selection criteria (two about BBFs and one a…
Anisotropic Turbulent Spectra in the Terrestrial Magnetosheath as Seen by the Cluster Spacecraft
Balogh, A.; Belmont, G.; Sahraoui, F. +3 more
Here we report the first three-dimensional spatial spectrum of the low frequency magnetic turbulence obtained from the four Cluster spacecraft in the terrestrial magnetosheath close to the magnetopause. We show that the turbulence is compressible and dominated by mirror structures, its energy is injected at a large scale kρ∼0.3 (l∼2000 km) via a m…
Single-spacecraft detection of rolled-up Kelvin-Helmholtz vortices at the flank magnetopause
RèMe, H.; Hasegawa, H.; Fujimoto, M. +3 more
Recent numerical simulations suggest that as soon as the Kelvin-Helmholtz instability (KHI) has grown nonlinearly to form a highly rolled-up vortex, plasma mixing is inevitably achieved within the vortex. Identification of rolled-up vortices by in situ measurements is therefore an important task as a step to establish the mechanism by which solar …
Cluster observations of reconnection due to the Kelvin-Helmholtz instability at the dawnside magnetospheric flank
Balogh, A.; Lavraud, B.; Kistler, L. M. +4 more
On 3 July 2001, the four Cluster satellites traversed along the dawnside magnetospheric flank and observed large variations in all plasma parameters. The estimated magnetopause boundary normals were oscillating in the z-direction and the normal component of the magnetic field showed systematic 2-3 min bipolar variations for 1 h when the IMF had a …
Kinetic simulations of ring current evolution during the Geospace Environment Modeling challenge events
Thomsen, M. F.; Mouikis, C. G.; Jordanova, V. K. +5 more
We investigate the temporal and spatial evolution of the ring current during two storms selected for study by the Geospace Environment Modeling (GEM) program using our kinetic drift-loss model coupled with a time-dependent plasmasphere model. We use geosynchronous data from LANL satellites to model the inflow of plasma from the magnetotail. We com…
Survey of large-amplitude flapping motions in the midtail current sheet
Nakamura, R.; Sergeev, V. A.; Baumjohann, W. +5 more
<P style="line-height: 20px;"> We surveyed fast current sheet crossings (flapping motions) over the distance range 10-30 RE in the magnetotail covered by the Geotail spacecraft. Since the local tilts of these dynamic sheets are large and variable in these events, we compare three different methods of evaluating current sheet norma…
Motion of observed structures calculated from multi-point magnetic field measurements: Application to Cluster
Balogh, A.; Zong, Q. -G.; Lucek, E. +5 more
A new method is described which calculates the velocity of observed, quasi-stationary structures at every moment in time from multi-point magnetic field measurements. Once the magnetic gradient tensor G = $\nabla$$\vec {B and the time variation of the magnetic field have been estimated at every moment, the velocity can then be determined, in princ…
Dynamics of thin current sheets associated with magnetotail reconnection
Balogh, A.; RèMe, H.; Fazakerley, A. N. +7 more
We have examined the detailed structure of thin current sheets and their evolution during a substorm interval on 24 August 2003, when Cluster experienced several rapid current sheet crossings within a couple of ion gyrotimes. These crossings took place during an interval of high-speed ion flows with BZ reversals and signatures of accele…