Search Publications
Solar cycle variations in the ionosphere of Mars as seen by multiple Mars Express data sets
Pätzold, M.; Lester, M.; Milan, S. E. +11 more
The response of the Martian ionosphere to solar activity is analyzed by taking into account variations in a range of parameters during four phases of the solar cycle throughout 2005-2012. Multiple Mars Express data sets have been used (such as Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) in Active Ionospheric Sounding, MARS…
On the propagation of a geoeffective coronal mass ejection during 15-17 March 2015
Webb, D. F.; Wang, Yuming; Shen, Fang +11 more
The largest geomagnetic storm so far, called 2015 St. Patrick's Day event, in the solar cycle 24 was produced by a fast coronal mass ejection (CME) originating on 15 March 2015. It was an initially west-oriented CME and expected to only cause a weak geomagnetic disturbance. Why did this CME finally cause such a large geomagnetic storm? We try to f…
An induced global magnetic field looping around the magnetotail of Venus
Barabash, Stas; Zhang, Tielong; Rong, Zhaojin +8 more
Venus serves as the prototype of solar wind interaction with unmagnetized planetary bodies with atmospheres. It has no intrinsic dipole or crustal magnetic field; the only magnetic field is believed to be formed by the draped interplanetary magnetic field (IMF). However, the large-scale magnetic field observed over the north polar region of Venus …
Shadowing and anisotropy of solar energetic ions at Mars measured by MAVEN during the March 2015 solar storm
Lee, Christina O.; Larson, Davin; Halekas, Jasper S. +4 more
The Solar Energetic Particle (SEP) Instrument on the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft is meant to characterize the variability of SEP fluxes at Mars. SEP ion precipitation is an important source of heating, ionization, and chemical changes in the upper atmosphere of Mars and may have played a substantial role in driving at…
Characteristics of quasi-monochromatic ULF waves in the Venusian foreshock
Zhang, Tielong; Mazelle, Christian; Lu, Quanming +5 more
The statistical properties of ULF waves observed upstream of Venus foreshock are investigated. The study is restricted to waves which are observed well below the local proton cyclotron frequency. Using the magnetic field observations from Venus Express between May 2006 and February 2012, 115 quasi-monochromatic ULF wave trains have been identified…
Statistical features of the global polarity reversal of the Venusian induced magnetosphere in response to the polarity change in interplanetary magnetic field
Nilsson, Hans; Zhang, Tielong; Edberg, Niklas J. T. +5 more
In this study we present the first statistical analysis on the effects of heliospheric current sheet crossings on the induced magnetosphere of Venus. These events are of particular interest because they lead to the reconfiguration of the induced magnetosphere with opposite polarity. We use a statistical approach based on 117 orbit pairs, and we st…
Is the flow-aligned component of IMF really able to impact the magnetic field structure of Venusian magnetotail?
Barabash, S.; Futaana, Y.; Wei, Y. +5 more
An earlier statistical survey suggested that the flow-aligned component of upstream interplanetary magnetic field (IMF) may play an important role in controlling the lobe asymmetries of the Venusian magnetotail. The tail current sheet would be displaced and the magnetic field configuration would show asymmetries with respect to the current sheet. …
Hemispheric asymmetry in the near-Venusian magnetotail during solar maximum
Zhang, T. L.; Baumjohann, W.; Xiao, S. D.
During solar minimum the near-Venusian magnetotail exhibits a hemispheric asymmetry in the cross-tail field distribution. It implies that the magnetic field lines in the -E hemisphere are wrapped more tightly around Venus than in the +E hemisphere. Therefore, a strong field reversal region occurs in the magnetotail, which is prone to the magnetic …
EMVIM: An empirical model for the magnetic field configuration near Venus
He, Maosheng; Vogt, Joachim; Zhang, Tielong +1 more
More than 2000 orbits of Venus Express magnetic field measurements are condensed into Empirical Model of Venusian Induced Magnetic fields (EMVIM), an empirical model to quantify the magnetic configuration in the Venusian magnetosphere at low altitude (<500 km) as a function of the upstream solar wind magnetic field (IMF components) and the sola…