Search Publications
Coronal Observations of CMEs. Report of Working Group A
Schwenn, R.; Pick, M.; Reiner, M. +15 more
CMEs have been observed for over 30 years with a wide variety of instruments. It is now possible to derive detailed and quantitative information on CME morphology, velocity, acceleration and mass. Flares associated with CMEs are observed in X-rays, and several different radio signatures are also seen. Optical and UV spectra of CMEs both on the dis…
Thin Current Sheets in the Magnetotail Observed by Cluster
Nakamura, R.; Baumjohann, W.; Asano, Y. +1 more
The dynamics of the current sheet is one of the most essential elements in magnetotail physics. Particularly, thin current sheets, which we define here as those with a thickness of less than several ion inertia lengths, are known to play an important role in the energy conversion process in the magnetotail. With its capability of multi-point obser…
Locations of Atmospheric Photoelectron Energy Peaks Within the Mars Environment
Coates, A. J.; Kallio, E.; Barabash, S. +13 more
By identifying peaks in the photoelectron spectrum produced by photoionization of CO2 in the Martian atmosphere, we have conducted a pilot study to determine the locations of these photoelectrons in the space around Mars. The significant result of this study is that these photoelectrons populate a region around Mars bounded externally b…
Plasma Moments in the Environment of Mars. Mars Express ASPERA-3 Observations
Coates, A. J.; Fedorov, A.; Barabash, S. +7 more
We present the first electron and ion moment maps (density, velocity and temperature) of the martian plasma environment, using data from the ELS and IMA sensors of the ASPERA-3 experiment onboard Mars Express. Moments are calculated by integration and by Gaussian fits to the phase space distribution. The methods of calculation and the calibration …
Energetic Particle Observations
Simnett, G. M.; Lario, D.; Klecker, B. +14 more
The characteristics of solar energetic particles (SEP) as observed in interplanetary space provide fundamental information about the origin of these particles, and the acceleration and propagation processes at the Sun and in interplanetary space. Furthermore, energetic particles provide information on the development and structure of coronal mass …
Observations of Vertical Reflections from the Topside Martian Ionosphere
Gurnett, D. A.; Morgan, D. D.; Orosei, R. +7 more
The Martian ionosphere has for the first time been probed by a low frequency topside radio wave sounder experiment (MARSIS) (Gurnett et al., 2005). The density profiles in the Martian ionosphere have for the first time been observed for solar zenith angles less than 48 degrees. The sounder spectrograms typically have a single trace of echoes, whic…
Bursty Bulk Flow Driven Turbulence in the Earth's Plasma Sheet
Nakamura, R.; Baumjohann, W.; Volwerk, M. +2 more
During the last several years significant progress has been made in understanding MHD turbulence in the Earth’s plasma sheet. Due to the statistically transitory properties of fluctuations, finite size and boundary effects, however, issues of fundamental importance remain unresolved. Here we concentrate on such intrinsic features of plasma sheet t…
The Hydrogen Exospheric Density Profile Measured with ASPERA-3/NPD
Barabash, S.; Lundin, R.; Holmström, M. +6 more
We have evaluated the Lyman-α limb emission from the exospheric hydrogen of Mars measured by the neutral particle detector of the ASPERA-3 instrument on Mars Express in 2004 at low solar activity (solar activity index = 42, F10.7=100). We derive estimates for the hydrogen exobase density, nH = 1010 m−3, …
Energization of Plasma Species by Intermittent Kinetic Alfvén Waves
Goossens, Marcel; Voitenko, Yuriy
We propose a new phase-mixing sweep model of coronal heating and solar wind acceleration based on dissipative properties of kinetic Alfvén waves (KAWs). The energy reservoir is provided by the intermittent ∼1 Hz MHD Alfvén waves excited at the coronal base by magnetic restructuring. These waves propagate upward along open magnetic field lines, pha…
ICMEs in the Outer Heliosphere and at High Latitudes: An Introduction
Richardson, J. D.; von Steiger, R.
Interplanetary coronal mass ejections (ICMEs) are observed at all latitudes and distances from which data are available. We discuss the radial evolution of ICMEs out to large distances and ICME properties at high latitudes. The internal pressure of ICMEs initially exceeds the ambient solar wind pressure and causes the ICMEs to expand in radial wid…