Search Publications
Dispersion relation analysis of turbulent magnetic field fluctuations in fast solar wind
Glassmeier, K. -H.; Narita, Y.; Perschke, C. +2 more
Physical processes of the energy transport in solar wind turbulence are a subject of intense studies, and different ideas exist to explain them. This manuscript describes the investigation of dispersion properties in short-wavelength magnetic turbulence during a rare high-speed solar wind event with a flow velocity of about 700 km s-1 u…
Profiles of electron temperature and Bz along Earth's magnetotail
Petrukovich, A. A.; Zelenyi, L. M.; Nakamura, R. +1 more
We study the electron temperature distribution and the structure of the current sheet along the magnetotail using simultaneous observations from THEMIS spacecraft. We perform a statistical study of 40 crossings of the current sheet when the three spacecraft THB, THC, and THD were distributed along the tail in the vicinity of midnight with coordina…
Dispersion of low frequency plasma waves upstream of the quasi-perpendicular terrestrial bow shock
Walker, S. N.; Balikhin, M. A.; Pope, S. A. +1 more
Low frequency waves in the foot of a supercritical quasi-perpendicular shock front have been observed since the very early in situ observations of the terrestrial bow shock (Guha et al., 1972). The great attention that has been devoted to these type of waves since the first observations is explained by the key role attributed to them in the proces…
Ray tracing of whistler-mode chorus elements: implications for generation mechanisms of rising and falling tone emissions
Nunn, D.; Omura, Y.; Yamaguchi, K. +1 more
Using a well-established magnetospheric very-low-frequency (VLF) ray tracing method, in this work we trace the propagation of individual rising- and falling-frequency elements of VLF chorus from their generation point in the equatorial region of the magnetosphere through to at least one reflection at the lower-hybrid resonance point. Unlike recent…
Gradient estimation using configurations of two or three spacecraft
Vogt, J.; Blagau, A.; Sorbalo, E. +1 more
The forthcoming three-satellite mission Swarm will allow us to investigate plasma processes and phenomena in the upper ionosphere from an in-situ multi-spacecraft perspective. Since with less than four points in space the spatiotemporal ambiguity cannot be resolved fully, analysis tools for estimating spatial gradients, wave vectors, or boundary p…
Non-adiabatic electron behaviour due to short-scale electric field structures at collisionless shock waves
Schwartz, S. J.; See, V.; Cameron, R. F.
Under sufficiently high electric field gradients, electron behaviour within exactly perpendicular shocks is unstable to the so-called trajectory instability. We extend previous work paying special attention to short-scale, high-amplitude structures as observed within the electric field profile. Via test particle simulations, we show that such stru…
Ion distributions upstream and downstream of the Earth's bow shock: first results from Vlasiator
Vainio, R.; Palmroth, M.; Pokhotelov, D. +3 more
A novel hybrid-Vlasov code, Vlasiator, is developed for global simulations of magnetospheric plasma kinetics. The code is applied to model the collisionless bow shock on scales of the Earth's magnetosphere in two spatial dimensions and three dimensions in velocity space retrieving ion distribution functions over the entire foreshock and magnetoshe…
A statistical study on O+ flux in the dayside magnetosheath
Nilsson, H.; Slapak, R.; Westerberg, L. G.
Studies on terrestrial oxygen ion (O+) escape into the interplanetary space have considered a number of different escape paths. Recent observations however suggest a yet insufficiently investigated additional escape route for hot O+: along open magnetic field lines in the high altitude cusp and mantle. Here we present a stati…
Dynamical processes in space: Cluster results
Escoubet, C. P.; Goldstein, M. L.; Taylor, M. G. G. T. +4 more
After 12 years of operations, the Cluster mission continues to successfully fulfil its scientific objectives. The main goal of the Cluster mission, comprised of four identical spacecraft, is to study in three dimensions small-scale plasma structures in key plasma regions of the Earth's environment: solar wind and bow shock, magnetopause, polar cus…
Cluster as current sheet surveyor in the magnetotail
Nakamura, R.; Baumjohann, W.; Narita, Y.
A novel analysis technique is presented to estimate the current sheet thickness unambiguously and directly, without associating time series data with spatial structure. The technique is a combination of eigenvalue analysis and minimum variance estimator adapted to Harris current sheet geometry, and needs one-time, four-point magnetic field data as…