Search Publications
A study of ionopause perturbation and associated boundary wave formation at Venus
Zhang, Tielong; Collinson, Glyn A.; Chong, Ghai Siung +3 more
Magnetometer and electron spectrometer data from Venus Express (VEX) are used to investigate the occurrence of boundary wave phenomenon occurring in the vicinity of the Venusian terminator. On 26 June 2006, VEX data show the ionosphere to be unmagnetized (≈0 nT), a common observation usually expected during solar maximum. This results in the respe…
Localization of whistler wave and turbulent spectra in the magnetotail region
Sharma, R. P.; Pathak, Neha; Sharma, Swati +2 more
Observations show that whistler waves play a very crucial role both in magnetic reconnection and turbulence. In this context, linear and nonlinear dynamical equations of whistler wave have been derived and further these equations have been solved numerically as well as semianalytically. For application purpose, magnetotail parameters have been cho…
Double-peaked core field of flux ropes during magnetic reconnection
Feng, Xueshang; Nakamura, Rumi; Wang, Rongsheng +2 more
A flux rope event observed in the magnetotail exhibits a double-peaked core field feature. The generation of such double-peaked feature within the flux rope is explored with Hall-MHD simulations and theoretical analysis based on multiple X line reconnection. Simulations with a guide field produce flux ropes bounded by two active X lines in the thi…
Relationship between electron field-aligned anisotropy and dawn-dusk magnetic field: Nine years of Cluster observations in the Earth magnetotail
Nakamura, R.; Artemyev, A.; Petrukovich, A. +1 more
We investigate the distribution and possible origins of thermal anisotropic electrons in the Earth's magnetotail, using 9 years of Cluster observations. We mainly focus on relation between electron anisotropy and Bz and By magnetic field components (in GSM coordinates). The anisotropy of electron population is characterized b…
Formation of multiple energy dispersion of H+, He+, and O+ ions in the inner magnetosphere in response to interplanetary shock
Tanaka, T.; Ebihara, Y.; Tsuji, H.
An interplanetary (IP) shock has a large impact on magnetospheric ions. Satellite observations have shown that soon after arrival of the IP shock, overall intensity of the ions rapidly increases and multiple energy dispersion appears in an energy-time spectrogram of the ions. In order to understand the response of the magnetospheric ions to IP sho…
Distribution of Field-Aligned Electron Events in the High-Altitude Polar Region: Cluster Observations
Dunlop, Malcolm; Carr, Chris; Torkar, Klaus +4 more
Field-aligned electrons (FAEs) are important for the energy transport in the solar wind-magnetosphere-ionosphere coupling. However, the distribution of FAEs and the concerning physical mechanism in different altitudes of the polar region are still unclear. In this paper, data from the Cluster spacecraft were used to study the characteristics of FA…
Validation of single spacecraft methods for collisionless shock velocity estimation
Pope, Simon A.; Walker, Simon N.; Collinson, Glyn +1 more
The velocity of a collisionless shock (CS) is an important parameter in the determination of the spatial scales of the shock. The spatial scales of the shock determine the processes that guide the energy dissipation, which is related to the nature of the shock. During the pre-ISEE era, estimations of relative shock-spacecraft velocity (VSh
Quasiperiodic field-aligned current dynamics associated with auroral undulations during a substorm recovery
Marghitu, O.; Vogt, J.; Bunescu, C. +2 more
A substorm recovery event in the early morning sector is explored by means of ground and spacecraft data. The ground data are provided by stations of the MIRACLE network, in northern Scandinavia and Svalbard, while spacecraft data are observed by the Cluster satellites, toward the end of the recovery phase. Additional information is provided by th…
Swept Forward Magnetic Field Variability in High-Latitude Regions of Saturn's Magnetosphere
Coates, A. J.; Dougherty, M. K.; Masters, A. +3 more
Swept forward field is the term given to configurations of magnetic field wherein the field lines deviate from the meridional planes of a planet in the direction of its rotation. Evidence is presented for swept-forward field configurations on Cassini orbits around Saturn from the first half of 2008. These orbits were selected on the basis of high …
Concerning the helium-to-hydrogen number density ratio in very slow ejecta and winds near solar minimum
Farrugia, C. J.; Galvin, A. B.; Vasquez, Bernard J. +2 more
Near the solar minimum the average value of the helium-to-proton number density ratio is a strong function of speed. The average ratios for both solar ejecta and ambient winds obey approximately the same relation with speed. At the lowest speeds, the ratio takes on small values near and below 0.01. Here winds and ejecta with very slow speeds (≲310…