Search Publications

Observation of a new type of low-frequency waves at comet 67P/Churyumov-Gerasimenko
DOI: 10.5194/angeo-33-1031-2015 Bibcode: 2015AnGeo..33.1031R

Altwegg, K.; Tsurutani, B. T.; Glassmeier, K. -H. +23 more

We report on magnetic field measurements made in the innermost coma of 67P/Churyumov-Gerasimenko in its low-activity state. Quasi-coherent, large-amplitude (δ B/B ~ 1), compressional magnetic field oscillations at ~ 40 mHz dominate the immediate plasma environment of the nucleus. This differs from previously studied cometary interaction regions wh…

2015 Annales Geophysicae
Rosetta 60
Internally and externally induced deformations of the magnetospheric equatorial current as inferred from spacecraft data
DOI: 10.5194/angeo-33-1-2015 Bibcode: 2015AnGeo..33....1T

Gordeev, E. I.; Tsyganenko, N. A.; Andreeva, V. A.

Based on a data pool of 79 yearly files of space magnetometer data by Polar, Cluster, Geotail, and THEMIS satellites between 1995 and 2013, we developed a new quantitative model of the global shape of the magnetospheric equatorial current sheet as a function of the Earth's dipole tilt angle, solar wind ram pressure, and interplanetary magnetic fie…

2015 Annales Geophysicae
Cluster 29
The relationship between plasmapause, solar wind and geomagnetic activity between 2007 and 2011
DOI: 10.5194/angeo-33-1271-2015 Bibcode: 2015AnGeo..33.1271V

Pierrard, V.; Rauch, J. -L.; Décréau, P. +3 more

Taking advantage of the Cluster satellite mission and especially the observations made by the instrument WHISPER to deduce the electron number density along the orbit of the satellites, we studied the relationships between the plasmapause positions (LPP) and the following LPP indicators: (a) solar wind coupling functions B

2015 Annales Geophysicae
Cluster 28
The far-ultraviolet main auroral emission at Jupiter - Part 1: Dawn-dusk brightness asymmetries
DOI: 10.5194/angeo-33-1203-2015 Bibcode: 2015AnGeo..33.1203B

Khurana, K. K.; Badman, S. V.; Bonfond, B. +6 more

The main auroral emission at Jupiter generally appears as a quasi-closed curtain centered around the magnetic pole. This auroral feature, which accounts for approximately half of the total power emitted by the aurorae in the ultraviolet range, is related to corotation enforcement currents in the middle magnetosphere. Early models for these current…

2015 Annales Geophysicae
eHST 26
Recent highlights from Cluster, the first 3-D magnetospheric mission
DOI: 10.5194/angeo-33-1221-2015 Bibcode: 2015AnGeo..33.1221E

Escoubet, C. P.; Goldstein, M. L.; Masson, A. +1 more

The Cluster mission has been operated successfully for 14 years. During this time period, the evolution of the orbit has enabled Cluster to sample many more magnetospheric regions than was initially anticipated. So far, the separation of the Cluster spacecraft has been changed more than 30 times and has ranged from a few kilometres up to 36 000 km…

2015 Annales Geophysicae
Cluster 17
O+ transport in the dayside magnetosheath and its dependence on the IMF direction
DOI: 10.5194/angeo-33-301-2015 Bibcode: 2015AnGeo..33..301S

Nilsson, H.; Slapak, R.; Larsson, R. +1 more

Recent studies have shown that the escape of oxygen ions (O+) into the magnetosheath along open magnetic field lines from the terrestrial cusp and mantle is significant. We present a study of how O+ transport in the dayside magnetosheath depends on the interplanetary magnetic field (IMF) direction. There are clear asymmetries…

2015 Annales Geophysicae
Cluster 15
The far-ultraviolet main auroral emission at Jupiter - Part 2: Vertical emission profile
DOI: 10.5194/angeo-33-1211-2015 Bibcode: 2015AnGeo..33.1211B

Khurana, K. K.; Badman, S. V.; Bonfond, B. +6 more

The aurorae at Jupiter are made up of many different features associated with a variety of generation mechanisms. The main auroral emission, also known as the main oval, is the most prominent of them as it accounts for approximately half of the total power emitted by the aurorae in the ultraviolet range. The energy of the precipitating electrons i…

2015 Annales Geophysicae
eHST 14
Multi-satellite study of the excitation of Pc3 and Pc4-5 ULF waves and their penetration across the plasmapause during the 2003 Halloween superstorm
DOI: 10.5194/angeo-33-1237-2015 Bibcode: 2015AnGeo..33.1237B

Tsinganos, K.; Daglis, I. A.; Mann, I. R. +5 more

We use multi-satellite and ground-based magnetic data to investigate the concurrent characteristics of Pc3 (22-100 mHz) and Pc4-5 (1-22 mHz) ultra-low-frequency (ULF) waves on the 31 October 2003 during the Halloween magnetic superstorm. ULF waves are seen in the Earth's magnetosphere, topside ionosphere, and Earth's surface, enabling an examinati…

2015 Annales Geophysicae
Cluster 12
Field-aligned chorus wave spectral power in Earth's outer radiation belt
DOI: 10.5194/angeo-33-583-2015 Bibcode: 2015AnGeo..33..583B

Daly, P. W.; Haaland, S. E.; Kronberg, E. A. +8 more

Chorus-type whistler waves are one of the most intense electromagnetic waves generated naturally in the magnetosphere. These waves have a substantial impact on the radiation belt dynamics as they are thought to contribute to electron acceleration and losses into the ionosphere through resonant wave-particle interaction. Our study is devoted to the…

2015 Annales Geophysicae
Cluster 11
Outflow of low-energy O+ ion beams observed during periods without substorms
DOI: 10.5194/angeo-33-333-2015 Bibcode: 2015AnGeo..33..333P

Dandouras, I.; Rème, H.; Parks, G. K. +5 more

Numerous observations have shown that ions flow out of the ionosphere during substorms with more fluxes leaving as the substorm intensity increases (Wilson et al., 2004). In this article we show observations of low-energy (few tens of electron volts) ionospheric ions flowing out periods without substorms, determined using the Wideband Imaging Came…

2015 Annales Geophysicae
Cluster 10