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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
Non-elliptic wavevector anisotropy for magnetohydrodynamic turbulence
DOI: 10.5194/angeo-33-1413-2015 Bibcode: 2015AnGeo..33.1413N

Narita, Y.

A model of non-elliptic wavevector anisotropy is developed for the inertial-range spectrum of magnetohydrodynamic turbulence and is presented in the two-dimensional wavevector domain spanning the directions parallel and perpendicular to the mean magnetic field.

The non-elliptic model is a variation of the elliptic model with different sca…

2015 Annales Geophysicae
Cluster 9
Experimental test of the ρ(1-α) evolution for rotational discontinuities: cluster magnetopause observations
DOI: 10.5194/angeo-33-79-2015 Bibcode: 2015AnGeo..33...79B

Marghitu, O.; Klecker, B.; Paschmann, G. +1 more

Rotational discontinuities (RDs) are governed by two relations: the Walén relation predicting that the plasma velocity observed in the deHoffmann-Teller frame equals the local Alfvén velocity and another relation that connects the variation in plasma mass density, ρ, to variations in the pressure anisotropy factor, α, defined as α: ≡(p

2015 Annales Geophysicae
Cluster 7
The dayside magnetopause location during radial interplanetary magnetic field periods: Cluster observation and model comparison
DOI: 10.5194/angeo-33-437-2015 Bibcode: 2015AnGeo..33..437H

Wang, H.; Shue, J. -H.; Huang, T. +2 more

The present work has investigated the midlatitudinal magnetopause locations under radial interplanetary field (RIMF) conditions. Among 262 (256) earthward (sunward) RIMF events from years of 2001 to 2009, Cluster satellites have crossed the magnetopause 22(12) times, with 10 (7) events occurring at midlatitudes. The observed midlatitudinal magneto…

2015 Annales Geophysicae
Cluster 7
Electron-scale nested quadrupole Hall field in Cluster observations of magnetic reconnection
DOI: 10.5194/angeo-33-719-2015 Bibcode: 2015AnGeo..33..719J

Jain, N.; Sharma, A. S.

This paper presents the first evidence of a new and unique feature of spontaneous reconnection at multiple sites in electron current sheet, viz. a "nested quadrupole" structure of the Hall field at electron scales, in Cluster observations. The new nested quadrupole is a consequence of electron-scale processes in reconnection. Whistler response of …

2015 Annales Geophysicae
Cluster 6