Search Publications
Non-elliptic wavevector anisotropy for magnetohydrodynamic turbulence
Narita, Y.
A model of non-elliptic wavevector anisotropy is developed for the inertial-range spectrum of magnetohydrodynamic turbulence and is presented in the two-dimensional wavevector domain spanning the directions parallel and perpendicular to the mean magnetic field.
The non-elliptic model is a variation of the elliptic model with different sca…
Experimental test of the ρ(1-α) evolution for rotational discontinuities: cluster magnetopause observations
Marghitu, O.; Klecker, B.; Paschmann, G. +1 more
Rotational discontinuities (RDs) are governed by two relations: the Walén relation predicting that the plasma velocity observed in the deHoffmann-Teller frame equals the local Alfvén velocity and another relation that connects the variation in plasma mass density, ρ, to variations in the pressure anisotropy factor, α, defined as α: ≡(p
The dayside magnetopause location during radial interplanetary magnetic field periods: Cluster observation and model comparison
Wang, H.; Shue, J. -H.; Huang, T. +2 more
The present work has investigated the midlatitudinal magnetopause locations under radial interplanetary field (RIMF) conditions. Among 262 (256) earthward (sunward) RIMF events from years of 2001 to 2009, Cluster satellites have crossed the magnetopause 22(12) times, with 10 (7) events occurring at midlatitudes. The observed midlatitudinal magneto…
Electron-scale nested quadrupole Hall field in Cluster observations of magnetic reconnection
Jain, N.; Sharma, A. S.
This paper presents the first evidence of a new and unique feature of spontaneous reconnection at multiple sites in electron current sheet, viz. a "nested quadrupole" structure of the Hall field at electron scales, in Cluster observations. The new nested quadrupole is a consequence of electron-scale processes in reconnection. Whistler response of …
In situ magnetotail magnetic flux calculation
Gordeev, E.; Shukhtina, M. A.
We explore two new modifications of the magnetotail magnetic flux (F) calculation algorithm based on the Petrinec and Russell (1996) (PR96) approach of the tail radius determination. Unlike in the PR96 model, the tail radius value is calculated at each time step based on simultaneous magnetotail and solar wind observations. Our former algorithm, d…
Adaptation of the de Hoffmann-Teller frame for quasi-perpendicular collisionless shocks
Narita, Y.; Motschmann, U.; Comişel, H.
The concept of the de Hoffmann-Teller frame is revisited for a high Mach-number quasi-perpendicular collisionless shock wave. Particle-in-cell simulation shows that the local magnetic field oscillations in the shock layer introduce a residual motional electric field in the de Hoffmann-Teller frame, which is misleading in that one may interpret tha…
Wide-banded NTC radiation: local to remote observations by the four Cluster satellites
Rauch, J. -L.; Décréau, P. M. E.; Canu, P. +7 more
The Cluster multi-point mission offers a unique collection of non-thermal continuum (NTC) radio waves observed in the 2-80 kHz frequency range over almost 15 years, from various view points over the radiating plasmasphere. Here we present rather infrequent case events, such as when primary electrostatic sources of such waves are embedded within th…
Physics of outflows near solar active regions
Price, D. J.; Taroyan, Y.
Hinode/EIS observations have revealed outflows near active regions which remain unexplained. An outflow region observed by the EUV Imaging Spectrometer (EIS) that appears slightly redshifted at low temperatures and blueshifted at higher temperatures is presented. We conduct simulations and use those to create synthetic line profiles in order to re…
Comparisons of electron acceleration efficiency among different structures during magnetic reconnection: a Cluster multicase study
Li, H.; Zhou, M.; Li, T. +2 more
Magnetic reconnection has long been believed to be an efficient engine for energetic electrons production. Four different structures have been proposed for electrons being energized: flux pileup region, density cavity located around the separatrix, magnetic island and thin current sheet. In this paper, we compare the electron acceleration efficien…
Self-consistent electrostatic simulations of reforming double layers in the downward current region of the aurora
Gunell, H.; Andersson, L.; De Keyser, J. +1 more
The plasma on a magnetic field line in the downward current region of the aurora is simulated using a Vlasov model. It is found that an electric field parallel to the magnetic fields is supported by a double layer moving toward higher altitude. The double layer accelerates electrons upward, and these electrons give rise to plasma waves and electro…