Search Publications
Upstream proton cyclotron waves at Venus near solar maximum
Lundin, R.; Volwerk, M.; Mazelle, C. +3 more
magnetometer data of Venus Express are analyzed for the occurrence of waves at the proton cyclotron frequency in the spacecraft frame in the upstream region of Venus, for conditions of rising solar activity. The data of two Venus years up to the time of highest sunspot number so far (1 Mar 2011 to 31 May 2012) are studied to reveal the properties …
Two states of magnetotail dipolarization fronts: A statistical study
Nakamura, R.; Baumjohann, W.; Volwerk, M. +2 more
We study the ion density and temperature in the predipolarization and postdipolarization plasma sheets in the Earth's magnetotail using 9 years (2001-2009) of Cluster data. For our study we selected cases when Cluster observed dipolarization fronts (DFs) with an earthward plasma flow greater than 150km/s. We perform a statistical study of the temp…
Kinematics of interacting CMEs of 25 and 28 September 2012
Srivastava, Nandita; Mishra, Wageesh; Singh, Talwinder
We have studied two coronal mass ejections (CMEs) that occurred on 25 and 28 September 2012 and interacted near the Earth. By fitting the Graduated Cylindrical Shell model on the SECCHI/COR2 images and applying the Stereoscopic Self-Similar Expansion method on the SECCHI/HI images, the initial direction of both the CMEs is estimated to be west of …
Intensities and spatiotemporal variability of equatorial noise emissions observed by the Cluster spacecraft
Santolík, O.; Němec, F.; Cornilleau-Wehrlin, N. +1 more
Equatorial noise (EN) emissions are electromagnetic waves observed in the equatorial region of the inner magnetosphere at frequencies between the proton cyclotron frequency and the lower hybrid frequency. We present the analysis of 2229 EN events identified in the Spatio-Temporal Analysis of Field Fluctuations (STAFF) experiment data of the Cluste…
Multispacecraft current estimates at swarm
Dunlop, M. W.; Shen, C.; Lühr, H. +8 more
During the first several months of the three-spacecraft Swarm mission all three spacecraft came repeatedly into close alignment, providing an ideal opportunity for validating the proposed dual-spacecraft method for estimating current density from the Swarm magnetic field data. Two of the Swarm spacecraft regularly fly side-by-side in closely simil…
Equatorial noise emissions with quasiperiodic modulation of wave intensity
Pickett, J. S.; Santolík, O.; Němec, F. +2 more
Equatorial noise (EN) emissions are electromagnetic wave events at frequencies between the proton cyclotron frequency and the lower hybrid frequency observed in the equatorial region of the inner magnetosphere. They propagate nearly perpendicular to the ambient magnetic field, and they exhibit a harmonic line structure characteristic of the proton…
Polytropic index of central plasma sheet ions based on MHD Bernoulli integral
Ma, Yuduan; Wang, Jing; Cao, Jinbin +8 more
This paper uses the data of Cluster from 2001 to 2009 to study the polytropic processes of central plasma sheet (CPS) ions. We first adopt the approach of MHD Bernoulli integral (MBI) to identify homogeneous streamflow tubes (quasi-invariant MBI regions) and then calculate the polytropic index of ions for those streamflow tubes whose outward elect…
A method to derive maps of ionospheric conductances, currents, and convection from the Swarm multisatellite mission
Escoubet, C. P.; Kauristie, K.; Amm, O. +7 more
The European Space Agency (ESA) Swarm spacecraft mission is the first multisatellite ionospheric mission with two low-orbiting spacecraft that are flying in parallel at a distance of ~100-140 km, thus allowing derivation of spatial gradients of ionospheric parameters not only along the orbits but also in the direction perpendicular to them. A thir…
Multiscale study of electron energization during unsteady reconnection events
Lapenta, Giovanni; El-Alaoui, Mostafa; Walker, Raymond J. +2 more
Understanding particle acceleration in the magnetotail during substorms requires knowledge of changes in the global magnetospheric configuration and the local regions of intense fields and microinstabilities caused by processes associated with reconnection. We simulated a substorm on 15 February 2008 by coupling the University of California, Los A…
Technique for diagnosing the flapping motion of magnetotail current sheets based on single-point magnetic field analysis
Barabash, S.; Futaana, Y.; Wei, Y. +5 more
The magnetotail current sheet is active and often flaps back and forth. Knowledge about the flapping motion of current sheet is essential to explore the related magnetotail dynamic processes, e.g., plasma instabilities. Due to the inability of single-point measurements to separate the spatial-temporal variation of magnetic field, the moving veloci…