Search Publications
A new multivariate time series data analysis technique: Automated detection of flux transfer events using Cluster data
Lavraud, B.; Wang, Y.; Karimabadi, H. +2 more
A new data mining technique called MineTool-TS is introduced which captures the time-lapse information in multivariate time series data through extraction of global features and metafeatures. This technique is developed into a JAVA-based data mining software which automates all the steps in the model building to make it more accessible to nonexper…
Comment on ``Evolution of Kelvin-Helmholtz activity on the dusk flank magnetopause'' by Foullon et al.
Hasegawa, Hiroshi
Abstract Available from http://www.agu.org
Multiple-spacecraft study of an extended magnetic structure in the solar wind
Inhester, B.; Zong, Q. -G.; Marsch, E. +6 more
An extended magnetic structure was observed consecutively by five spacecraft (ACE, WIND, STEREO A and B, and CLUSTER) in the solar wind on 15 January 2007. The similar bipolar magnetic field variations from five spacecraft suggest that the magnetic structure is two-dimensional. The abrupt disappearance of the beam electrons in the core of the stru…
Short-period variability in the galactic cosmic ray intensity: High statistical resolution observations and interpretation around the time of a Forbush decrease in August 2006
Mulligan, T.; Galametz, M.; Leske, R. A. +4 more
On 20 August 2006 a Forbush decrease observed at Polar in the Earth's magnetosphere was also seen at the INTEGRAL spacecraft outside the magnetosphere during a very active time in the solar wind. High-resolution energetic particle data from ACE SIS, the Polar high-sensitivity telescope, and INTEGRAL's Ge detector saturation rate, which measures th…
Multipoint, high time resolution galactic cosmic ray observations associated with two interplanetary coronal mass ejections
Mulligan, T.; Galametz, M.; Spence, H. E. +3 more
Galactic cosmic rays (GCRs) play an important role in our understanding of the interplanetary medium (IPM). The causes of their short timescale variations, however, remain largely unexplored. In this paper, we compare high time resolution, multipoint space-based GCR data to explore structures in the IPM that cause these variations. To ensure that …
Cluster observations of energetic electron flux variations within the plasma sheet
Dandouras, I.; McPherron, R. L.; Baker, D. N. +3 more
The variability of energetic electron fluxes (>40 keV) within the plasma sheet is explored using measurements from the Cluster spacecraft from 2001 through 2005. Only cases where the spacecraft remains inside the plasma sheet throughout the event are considered. Interesting cases were found using a combination of automated methods and visual in…
Observations and modeling of particle dispersion signatures at a hot flow anomaly
Dandouras, I.; Lucek, E. A.; Tjulin, A.
We analyze a hot flow anomaly (HFA) event that the Cluster spacecraft encountered on 22 April 2008. HFAs are regions of hot, highly deflected ion flow near planetary bow shocks that are created from interactions between tangential discontinuities in the solar wind and the bow shock. This HFA event is studied in detail because it is flanked by supr…
A novel metric for coronal MHD models
Wiltberger, M.; de Toma, G.; Riley, P. +6 more
In the interest of quantitatively assessing the capabilities of coronal MHD models, we have developed a metric that compares the structures of the white light corona observed with SOHO LASCO C2 to model predictions. The MAS model is compared to C2 observations from two Carrington rotations during solar cycle 23, CR1913 and CR1984, which were near …
Modulation of NTC frequencies by Pc5 ULF pulsations: Experimental test of the generation mechanism and magnetoseismology of the emitting surface
Grimald, S.; Foullon, C.; Décréau, P. M. E. +3 more
Nonthermal continuum (NTC) radiation is believed to be emitted by the conversion of an electrostatic wave into an electromagnetic one, which takes place at the Earth's magnetic equator. It is generally accepted that the frequency of the electrostatic wave at the source meets a local characteristic frequency placed in between two multiples of the e…
Cluster multispacecraft measurement of spatial scales of foreshock Langmuir waves
Pickett, J. S.; Dudok de Wit, T.; Santolik, O. +1 more
In this article, we present the first multispacecraft study of spatial scales of Langmuir wave packets in the terrestrial foreshock. We used data from the Wideband Data (WBD) instrument on the Cluster satellites to identify simultaneous observations of the same wave packet on multiple spacecraft at very small separations. To overcome instrumental …