Search Publications
Statistical altitude distribution of the auroral density cavity
Karlsson, T.; Li, B.; Marklund, G. T. +1 more
The statistical altitude distribution of auroral density cavities located between 3.0 and 6.5 RE is investigated using in situ observations from flux tubes exhibiting auroral acceleration. The locations of the observations are described using a pseudo altitude derived from the distribution of the parallel potential drop above and below …
Propagation characteristics of young hot flow anomalies near the bow shock: Cluster observations
Dandouras, I.; Zhang, H.; Zong, Q. -G. +9 more
Based on Cluster observations, the propagation velocities and normal directions of hot flow anomaly (HFA) boundaries upstream the Earth's bow shock are calculated. Twenty-one young HFAs, which have clear leading and trailing boundaries, were selected, and multispacecraft timing method considering errors was employed for the investigation. Accordin…
Cassini VIMS observations of H3+ emission on the nightside of Jupiter
Baines, Kevin H.; Brown, Robert H.; O'Donoghue, James +10 more
We present the first detailed analysis of H3+ nightside emission from Jupiter, using Visual and Infrared Mapping Spectrometer (VIMS) data from the Cassini flyby in 2000-2001, producing the first Jovian maps of nightside H3+ emission, temperature, and column density. Using these, we identify and character…
The ULF wave foreshock boundary: Cluster observations
Mazelle, Christian; Andrés, Nahuel; Meziane, Karim +2 more
The interaction of backstreaming ions with the incoming solar wind in the upstream region of the bow shock gives rise to a number of plasma instabilities from which ultralow frequency (ULF) waves can grow. Because of their finite growth rate, the ULF waves are spatially localized in the foreshock region. Previous studies have reported observationa…
Case and statistical studies on the evolution of hot flow anomalies
Zhao, L. L.; Zhang, H.; Wang, S. +1 more
Hot flow anomalies (HFAs) frequently observed near Earth's bow shock are phenomena resulting from the interaction between interplanetary discontinuities and Earth's bow shock. We identify 199 HFA events using Cluster data from 2001 to 2010 and divide these events into four categories according to the dynamic pressure profile, namely, "-+," "+-," "…
A new stationary analytical model of the heliospheric current sheet and the plasma sheet
Malova, Helmi V.; Kislov, Roman A.; Khabarova, Olga V.
We develop a single-fluid 2-D analytical model of the axially symmetric thin heliospheric current sheet (HCS) embedded into the heliospheric plasma sheet (HPS). A HCS-HPS system has a shape of a relatively thin plasma disk limited by separatrices that also represent current sheets, which is in agreement with Ulysses observations in the aphelion, w…
Estimation of cold plasma outflow during geomagnetic storms
André, M.; Eriksson, A.; Haaland, S. +11 more
Low-energy ions of ionospheric origin constitute a significant contributor to the magnetospheric plasma population. Measuring cold ions is difficult though. Observations have to be done at sufficiently high altitudes and typically in regions of space where spacecraft attain a positive charge due to solar illumination. Cold ions are therefore shiel…
Sustained lobe reconnection in Saturn's magnetotail
Thomsen, M. F.; Jackman, C. M.; Kurth, W. S. +3 more
The degree to which solar wind driving may affect Saturn's magnetosphere is not yet fully understood. We present observations that suggest that under some conditions the solar wind does govern the character of the plasma sheet in Saturn's outer magnetosphere. On 16 September 2006, the Cassini spacecraft, at a radial distance of 37 Rs ne…
The impact of a slow interplanetary coronal mass ejection on Venus
Barabash, Stas; Futaana, Yoshifumi; Collinson, Glyn A. +8 more
We present Venus Express observations of the impact of a slow interplanetary coronal mass ejection (ICME), which struck Venus on 23 December 2006, creating unusual quasi steady state upstream conditions for the 2 h close to periapsis: an enhanced (∼ nT) interplanetary magnetic field (IMF), radially aligned with the Sun-Venus line; and a dense (∼ c…
What is the nature of magnetosheath FTEs?
Robert, Patrick; Louarn, Philippe; Fontaine, Dominique +3 more
Cluster multipoint measurements are used to study two successive magnetosheath flux transfer events (FTEs). Magnetic field lines in the leading region are found to be closed magnetospheric field lines. For event 1 these field lines are wounded up by a large current structure oriented eastward and moving poleward. Conversely, the trailing region co…