Annales Geophysicae (ANGEO) is an international, multi- and inter-disciplinary scientific open-access journal in the field of solar–terrestrial physics. ANGEO publishes original articles and short communications (letters) in the sciences of the Sun–Earth system, including the science of space weather, the solar–terrestrial plasma physics, and the Earth's atmosphere.
This paper presents recent highlights from the Cluster mission on solar wind turbulence, magnetopause asymmetries and magnetosheath density enhancements, dipolarisation currents, reconnection variability, FTE in greatest detail, plasmaspheric wind and re-filling of the plasmasphere, radiation belts, updates of magnetospheric electric and magnetic field models, and magnetosheath and magnetopause properties under low Mach number. Public access to all high-resolution data (CSA) is also presented.
C.P. Escoubet, A. Masson, H. Laakso, and M.L. Goldstein
We present a first report on magnetic field measurements made in the coma of comet 67P/C-G in its low-activity state. The plasma environment is dominated by quasi-coherent, large-amplitude, compressional magnetic field oscillations around 40mHz, differing from the observations at strongly active comets where waves at the cometary ion gyro-frequencies are the main feature. We propose a cross-field current instability associated with the newborn cometary ions as a possible source mechanism.
I. Richter, C. Koenders, H.-U. Auster, D. Fruehauff, C. Goetz, P. Heinisch, C. Perschke, U. Motschmann, B. Stoll, K. Altwegg, J. Burch, C. Carr, E. Cupido, A. Eriksson, P. Henri, R. Goldstein, J.-P. Lebreton, P. Mokashi, Z. Nemeth, H. Nilsson, M. Rubin, K. Szego, B. T. Tsurutani, C. Vallat, M. Volwerk, and K.-H. Glassmeier
Total electron content (TEC) between low-Earth-orbit (LEO) satellites and the Global Navigation Satellite System (GNSS) satellites can be used to constrain three-dimensional morphology of equatorial plasma bubbles (EPBs). TEC gradient observed along the LEO track is strongest when the corresponding GNSS satellite is located equatorward and westward of the LEO satellite. This anisotropy supports the idea that EPBs have three-dimensional shell structures.
J. Park, H. Lühr, and M. Noja
Rotational discontinuities (RDs) in plasma allow a magnetic connection between different plasma regimes. One of their defining relations describes a balance between changes in plasma mass density and pressure anisotropy. The paper uses the high-time-resolution data from the Cluster satellites to directly test that relation at the terrestrial magnetopause, when standard analysis predicts that this boundary behaves like an RD. The experimental evidence shows that the said relation is not fulfilled.
A. Blagau, G. Paschmann, B. Klecker, and O. Marghitu
A new quantitative model of the global shape of the neutral sheet in the Earth's magnetosphere is developed, parameterized by the dipole tilt, solar wind pressure, and IMF By and Bz. The model is based on data from the Polar, Cluster, Geotail, and Themis satellites taken in 1995-2013. The paper quantifies and further explains our earlier finding of the bowl-shaped deformation of the neutral sheet due to the Earth's dipole tilt (Tsyganenko and Andreeva, GRL, v.41(4), 2014).
N. A. Tsyganenko, V. A. Andreeva, and E. I. Gordeev