323 citations · 3k across the 112 of their papers we have counts for
45 papers · 1 filter
Entropic Force in MHD, MHD turbulence, and the Entropy-Kinetic Equation
W. Baumjohann, R. A. Treumann
Following earlier work, reference is made to the classical entropic force which results from spatially variable disorder, an exclusively repulsive force. In terms of macroscopic va…
Auroral Kilometric Radiation -- the Electron Cyclotron Maser Paradigm
W. Baumjohann, R. A. Treumann
Auroral kilometric radiation (AKR) is the paradigm of intense radio emission from planetary magnetospheres. Being close to the electron gyro frequency and/or its lower harmonics, i…
Diffuse Josephson Radiation in Turbulence
R. A. Treumann, Wolfgang Baumjohann
The possibility of generating diffuse radiation in extended astronomical media by plasma turbulence is investigated under the assumption that the turbulence can be understood as an…
MMS direct observations of kinetic-scale shock self-reformation
Zhongwei Yang, Ying D. Liu, Andreas Johlander +6
Studies of shocks have long suggested that a shock can undergo cyclically self-reformation in a time scale of ion cyclotron period. This process has been proposed as a primary mech…
Possible phase transition in plasma mirror modes
R. A. Treumann, Wolfgang Baumjohann
Mirror modes in collisionless high-temperature plasmas represent macroscopic high-temperature quasi-superconductors. We explicitly calculate the bouncing electron contribution to t…
Topside Reconnection
R. A. Treumann, Wolfgang Baumjohann
It is proposed that reconnection would be a main mechanism governing the plasma processes on auroral time scales in the topside ionosphere/high-latitude magnetosphere transition. I…
Auroral kilometric radiation and electron pairing
R. A. Treumann, Wolfgang Baumjohann
We suggest that pairing of bouncing medium-energy electrons in the auroral upward current region close to the mirror points may play a role in driving the electron cyclotron maser…
Electron pairing in mirror modes: Surpassing the quasilinear limit
R. A. Treumann, W. Baumjohann
The mirror mode evolving in collisionless magnetised high-temperature thermally anisotropic plasmas is shown to develop an interesting macro-state. Starting as a classical zero fre…
Seeds for collisionless reconnection
R. A. Treumann, Wolfgang Baumjohann
A stationary, two-dimensional, and non-driven antiparallel magnetic field configuration consisting of a central current film, flanked by two non-magnetic domains of electron inerti…
On the deviation from Maxwellian of the ion velocity distribution functions in the turbulent magnetosheath
Silvia Perri, D. Perrone, E. Yordanova +20
The degree of deviation from the thermodynamic equilibrium in the ion velocity distribution functions (VDFs), measured by the Magnetospheric Multiscale (MMS) mission in the Earth's…
On the applicability of Taylor's hypothesis in streaming magnetohydrodynamic turbulence
R. A. Treumann, W. Baumjohann, Yasuhito Narita
We examine the range of applicability of Taylor's hypothesis used in observations of magnetic turbulence in the solar wind. We do not refer to turbulence theory. We simply ask whet…
On the ion-inertial range density power spectra in solar wind turbulence
R. A. Treumann, W. Baumjohann, Yasuhito Narita
A model-independent first-principle first-order investigation of the shape of turbulent density-power spectra in the ion-inertial range of the solar wind at 1 AU is presented. De-m…
Electron-Scale Dynamics of the Diffusion Region during Symmetric Magnetic Reconnection in Space
R. B. Torbert, J. L. Burch, T. D. Phan +46
Magnetic reconnection is an energy conversion process important in many astrophysical contexts including the Earth's magnetosphere, where the process can be investigated in-situ. H…
The mirror mode: A "superconducting'' space plasma analogue
R. A. Treumann, W. Baumjohann
We examine the physics of the magnetic mirror mode in its final state of saturation, the thermodynamic equilibrium, to demonstrate that the mirror mode is the analogue of a superco…
Electron mirror branch: Observational evidence from "historical" AMPTE-IRM and Equator-S measurements
R. A. Treumann, W. Baumjohann
Based on now historical magnetic and plasma data and available wave spectra from the AMPTE-IRM spacecraft, and on as well historical Equator-S high-cadence magnetic field observati…
Sub-ionospheric AKR: A possible mechanism for its transport down from the topside generation region to the F layer and ground
R. A. Treumann, W. Baumjohann, J. LaBelle
Recent theoretical work shows that "electron exhausts", elongated regions of depleted electron density shown by PIC codes to be generated in collisionless reconnection, can in prin…
The usefulness of Poynting's theorem in magnetic turbulence
R. A. Treumann, W. Baumjohann
We rewrite Poynting's theorem, already used in a previous publication (Treumann & Baumjohann 2017) to derive relations between the turbulent magnetic and electric power spectral de…
Electron scale structures and magnetic reconnection signatures in the turbulent magnetosheath
E. Yordanova, Z. Vörös, A. Varsani +26
Collisionless space plasma turbulence can generate reconnecting thin current sheets as suggested by recent results of numerical magnetohydrodynamic simulations. The MMS mission pro…
Causal Kinetic Equation of Non-equilibrium Plasmas
R. A. Treumann, W. Baumjohann
Statistical plasma theory far from thermal equilibrium is subject to Liouville's equation which is at the base of the BBGKY hierarchical approach to plasma kinetic theory from whic…
The geomagnetic/magneto-telluric induction problem with spatial conductivity fluctuations
R. A. Treumann, W. Baumjohann
The electromagnetic induction equation (Helmholtz equation) for the electrically conducting Earth is generalised to the inclusion of a spatially fluctuating internal conductivity s…
Conductivity spectrum and dispersion relation in solar wind turbulence
R. A. Treumann, W. Baumjohann
Magnetic turbulence in the solar wind is treated from the point of view of electrodynamics. This can be done based on the use of Poynting's theorem attributing all turbulent dynami…
Electron cyclotron maser instability (ECMI) in strong magnetic guide field reconnection
R. A. Treumann, W. Baumjohann
Reconnection in strong current-aligned magnetic guide fields allows for the excitation of the electron-cyclotron-maser instability and emission of electromagnetic radiationfrom the…
Poynting's theorem in magnetic turbulence
R. A. Treumann, W. Baumjohann
Poynting's theorem is used to obtain an expression for the turbulent power-spectral density as function of frequency and wavenumber in low-frequency magnetic turbulence. No referen…
Inverse scattering problem in turbulent magnetic fluctuations
R. A. Treumann, W. Baumjohann, Y. Narita
We apply a particular form of the inverse scattering theory to turbulent magnetic fluctuations in a plasma. In the present note we develop the theory, formulate the magnetic fluctu…