Search Publications
A new three-dimensional magnetopause model with a support vector regression machine and a large database of multiple spacecraft observations
Wang, Y.; Merka, J.; Šafránková, J. +6 more
We present results from a new three-dimensional empirical magnetopause model based on 15,089 magnetopause crossings from 23 spacecraft. To construct the model, we introduce a Support Vector Regression Machine (SVRM) technique with a systematic approach that balances model smoothness with fitting accuracy to produce a model that reveals the manner …
Magnetosonic wave instability by proton ring distributions: Simultaneous data and modeling
Xiao, Fuliang; Yang, Chang; Zhou, Qinghua +3 more
Simultaneous observations of enhanced fast magnetosonic (MS) waves and distinct proton ring distributions collected by Cluster satellite near the location L= 4-5 on 28 May 2005 are analyzed to study instability of MS waves. A sum of subtracted bi-Maxwellian components is utilized to fit the observed proton (2-10 keV) ring distributions. A ray-trac…
Plasma in the near Venus tail: Venus Express observations
Fedorov, A.; Barabash, S.; Lundin, R. +5 more
Although Venus has no global intrinsic magnetic fields, it possesses a long magnetotail of induced origin. The topology of the tail is determined by the interplanetary magnetic field orientation. We present recent plasma and magnetic field observations in the near Venus tail (X≥-3RV) made by the Venus Express spacecraft. We show that io…
Slow magnetosonic waves detected in reconnection diffusion region in the Earth's magnetotail
Zhang, T. L.; Dandouras, I.; Cao, J. B. +4 more
We studied the ULF waves with a period of 30 s in the ion diffusion region of reconnection observed by Cluster satellites on 21 August 2002. The fast convective tailward ion flow accompanied with a large southward magnetic field component, a strong Hall magnetic field, and a Hall electric field demonstrates that the Cluster satellites are located …
Flow bouncing and electron injection observed by Cluster
Petrukovich, A. A.; Daly, P. W.; Khotyaintsev, Y. +14 more
Characteristics of particles and fields in the flow-bouncing region are studied based on multipoint observations from Cluster located at 13-15RE downtail during a substorm event around 12:50 UT on 7 September 2007. The Cluster spacecraft were separated by a distance of up to 10,000 km and allowed to determine the mesoscale evolution of …
The plasma density distribution in the inner region of Saturn's magnetosphere
Gurnett, D. A.; Persoon, A. M.; Kurth, W. S. +3 more
Electron density measurements derived from the upper hybrid resonance frequency have been obtained from the Cassini Radio and Plasma Wave Science experiment over a 7 year period from 28 October 2004 through 7 November 2011. Additional density measurements inside the orbit of Enceladus and outside the orbit of Rhea have made it possible to expand a…
Cluster observations of ∂Bz/∂x during growth phase magnetotail stretching intervals
Petrukovich, A. A.; Nakamura, R.; Baumjohann, W. +2 more
We study a statistics of ∂Bz/∂x in a thin stretching current sheet (substorm growth phases) observed by Cluster between 8 and 18 RE downtail. After 2005, spacecraft separation allowed to measure directly this derivative of Bz along the tail axis. The near-tail events (within 14 RE) exhibited a straight d…
EMIC triggered chorus emissions in Cluster data
Pickett, J. S.; SantolíK, O.; Cornilleau-Wehrlin, N. +6 more
Electromagnetic ion cyclotron (EMIC) triggered chorus emissions have recently been a subject of several experimental, theoretical and simulation case studies, noting their similarities with whistler-mode chorus. We perform a survey of 8 years of Cluster data in order to increase the database of EMIC triggered emissions. The results of this is that…
Azimuthal directions of equatorial noise propagation determined using 10 years of data from the Cluster spacecraft
Pickett, J. S.; Santolík, O.; Němec, F. +2 more
Equatorial noise (EN) emissions are electromagnetic waves at frequencies between the proton cyclotron frequency and the lower hybrid frequency routinely observed within a few degrees of the geomagnetic equator at radial distances from about 2 to 6 RE. They propagate in the extraordinary (fast magnetosonic) mode nearly perpendicularly to…
Conjugate observations of quasi-periodic emissions by Cluster and DEMETER spacecraft
Pickett, J. S.; Parrot, M.; SantolíK, O. +3 more
<title type="main">Abstract<p label="1">Quasi-periodic (QP) emissions are electromagnetic emissions at frequencies of about 0.5-4 kHz that are characterized by a periodic time modulation of the wave intensity. Typical periods of this modulation are on the order of minutes. We present a case study of a large-scale long-lasting QP event …