Search Publications
The flapping motion of the Venusian magnetotail: Venus Express observations
Barabash, S.; Futaana, Y.; Wei, Y. +7 more
With a newly developed technique and magnetic field measurements obtained by the magnetometer on Venus Express, we study the flapping motion of the Venusian magnetotail. We find that the flapping motion generally comprises contributions both from a nonpropagating steady flapping and a propagating kink-like flapping. The flapping motion tilts the c…
Analysis of a coronal mass ejection and corotating interaction region as they travel from the Sun passing Venus, Earth, Mars, and Saturn
Harra, L. K.; Arridge, C. S.; Matthews, S. A. +2 more
During June 2010 a good alignment in the solar system between Venus, STEREO-B, Mars, and Saturn provided an excellent opportunity to study the propagation of a coronal mass ejection (CME) and closely occurring corotating interaction region (CIR) from the Sun to Saturn. The CME erupted from the Sun at 01:30 UT on 20 June 2010,with v≈ 600 km s-…
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 …
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…
Space weather effects on the bow shock, the magnetic barrier, and the ion composition boundary at Venus
Kallio, E.; Szego, K.; Fraenz, M. +4 more
We present a statistical study on the interaction between interplanetary coronal mass ejections (ICMEs) and the induced magnetosphere of Venus when the peak magnetic field of the magnetic barrier was anomalously large (>65 nT). Based on the entire available Venus Express data set from April 2006 to October 2014, we selected 42 events and analyz…
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…
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…
Characterizing the low-altitude magnetic belt at Venus: Complementary observations from the Pioneer Venus Orbiter and Venus Express
Luhmann, J. G.; Russell, C. T.; Wei, H. Y. +4 more
Using Venus Express, Zhang et al. (2012b) identified strong magnetic field enhancements at low altitudes over the north polar region of Venus as giant flux ropes. Strong fields at low altitudes were also observed during the Pioneer Venus Orbiter mission, but at low latitudes near the subsolar and midnight regions. We examine the possibility that t…
Solar zenith angle-dependent asymmetries in Venusian bow shock location revealed by Venus Express
Zhang, Tielong; Rong, Zhaojin; Futaana, Yoshifumi +8 more
It has been long known that the Venusian bow shock (BS) location is asymmetric from the observations of the long-lived Pioneer Venus Orbiter mission. The Venus Express (VEX) mission crossed BS near perpendicularly not only in the terminator region but also in the near-subsolar and tail regions. Taking the advantage of VEX orbit geometry, we examin…
Internal structure of a coronal mass ejection revealed by Akatsuki radio occultation observations
Isobe, H.; Imamura, T.; Häusler, B. +6 more
A coronal mass ejection (CME) was observed at the heliocentric distance of 12.7 Rυ by radio occultation measurements using the Akatsuki spacecraft. The temporal developments of the bulk velocity and the electron column density along the raypath traversing the CME were obtained, and under the assumption that the irregularities are transp…