Search Publications
Estimating the magnetic energy inside traveling compression regions
Nakamura, R.; Baumjohann, W.; Semenov, V. S. +3 more
We investigate a series of six TCRs (traveling compression regions), appearing in the course of a small substorm on 19 September 2001. Except for two of these TCRs, all Cluster spacecraft were located in the lobe and detected the typical signatures of TCRs, i.e., compressions in |B| and bipolar Bz variations. We use these perturbations …
Velocity fluctuations in polar solar wind: a comparison between different solar cycles
Bavassano, B.; Bruno, R.; D'Amicis, R.
The polar solar wind is a fast, tenuous and steady flow that, with the exception of a relatively short phase around the Sun's activity maximum, fills the high-latitude heliosphere. The polar wind properties have been extensively investigated by Ulysses, the first spacecraft able to perform in-situ measurements in the high-latitude heliosphere. The…
The role of lateral magnetic reconnection in solar eruptive events
Poedts, S.; Bemporad, A.; Soenen, A. +1 more
On 10-11 December 2005 a slow CME occurred in between two coronal streamers in the Western Hemisphere. SOHO/MDI magnetograms show a multipolar magnetic configuration at the photosphere consisting of a complex of active regions located at the CME source and two bipoles at the base of the lateral coronal streamers. White light observations reveal th…
Cluster spacecraft observations of a ULF wave enhanced by Space Plasma Exploration by Active Radar (SPEAR)
Yeoman, T. K.; Fear, R. C.; Badman, S. V. +3 more
Space Plasma Exploration by Active Radar (SPEAR) is a high-latitude ionospheric heating facility capable of exciting ULF waves on local magnetic field lines. We examine an interval from 1 February 2006 when SPEAR was transmitting a 1 Hz modulation signal with a 10 min on-off cycle. Ground magnetometer data indicated that SPEAR modulated currents i…
Inverse reconstruction technique based on time-dependent Petschek-type reconnection model: first application to THEMIS magnetotail observations
Ivanova, V.; Liu, J.; Semenov, V. +2 more
We apply the inverse reconstruction technique based on the two-dimensional time-dependent Petschek-type reconnection model to a dual bipolar magnetic structure observed by THEMIS B probe in the Earth's magnetotail during a substorm on 22 February 2008 around 04:35 UT. The technique exploits the recorded bipolar magnetic field variation as an input…
Coronal mass ejections, type II radio bursts, and solar energetic particle events in the SOHO era
Kaiser, M. L.; Howard, R. A.; Gopalswamy, N. +5 more
Using the extensive and uniform data on coronal mass ejections (CMEs), solar energetic particle (SEP) events, and type II radio bursts during the SOHO era, we discuss how the CME properties such as speed, width and solar-source longitude decide whether CMEs are associated with type II radio bursts and SEP events. We discuss why some radio-quiet CM…
Transient and localized processes in the magnetotail: a review
Zelenyi, L. M.; Sauvaud, J. -A.; Louarn, P. +16 more
Many phenomena in the Earth's magnetotail have characteristic temporal scales of several minutes and spatial scales of a few Earth radii (RE). Examples of such transient and localized mesoscale phenomena are bursty bulk flows, beamlets, energy dispersed ion beams, flux ropes, traveling compression regions, night-side flux transfer event…
Spectra and anisotropy of magnetic fluctuations in the Earth's magnetosheath: Cluster observations
Alexandrova, O.; Mangeney, A.; Lacombe, C.
We investigate the spectral shape, the anisotropy of the wave vector distributions and the anisotropy of the amplitudes of the magnetic fluctuations in the Earth's magnetosheath within a broad range of frequencies [10-3, 10] Hz which corresponds to spatial scales from ~10 to 105 km. We present the first observations of a Kolm…
Processes and mechanisms governing the initiation and propagation of CMEs
Vršnak, B.
The most important observational characteristics of coronal mass ejections (CMEs) are summarized, emphasizing those aspects which are relevant for testing physical concepts employed to explain the CME take-off and propagation. In particular, the kinematics, scalings, and the CME-flare relationship are stressed. Special attention is paid to 3-dimen…
A comparison of coronal mass ejections identified by manual and automatic methods
Gopalswamy, N.; Michalek, G.; Yashiro, S.
Coronal mass ejections (CMEs) are related to many phenomena (e.g. flares, solar energetic particles, geomagnetic storms), thus compiling of event catalogs is important for a global understanding these phenomena. CMEs have been identified manually for a long time, but in the SOHO era, automatic identification methods are being developed. In order t…