Search Publications

Rosetta and Mars Express observations of the influence of high solar wind pressure on the Martian plasma environment
DOI: 10.5194/angeo-27-4533-2009 Bibcode: 2009AnGeo..27.4533E

Barabash, S.; Lundin, R.; Fränz, M. +18 more

We report on new simultaneous in-situ observations at Mars from Rosetta and Mars Express (MEX) on how the Martian plasma environment is affected by high pressure solar wind. A significant sharp increase in solar wind density, magnetic field strength and turbulence followed by a gradual increase in solar wind velocity is observed during ~24 h in th…

2009 Annales Geophysicae
MEx Rosetta 20
Evaluation of magnetic helicity density in the wave number domain using multi-point measurements in space
DOI: 10.5194/angeo-27-3967-2009 Bibcode: 2009AnGeo..27.3967N

Glassmeier, K. -H.; Narita, Y.; Kleindienst, G.

We develop an estimator for the magnetic helicity density, a measure of the spiral geometry of magnetic field lines, in the wave number domain as a wave diagnostic tool based on multi-point measurements in space. The estimator is numerically tested with a synthetic data set and then applied to an observation of magnetic field fluctuations in the E…

2009 Annales Geophysicae
Cluster 20
Substorm activity in Venus's magnetotail
DOI: 10.5194/angeo-27-2321-2009 Bibcode: 2009AnGeo..27.2321V

Barabash, S.; Futaana, Y.; Zhang, T. L. +5 more

The magnetotail of the induced magnetosphere of Venus is investigated through the magnetic field and plasma data of Venus Express. A comparison is made between two neutral sheet crossings. One crossing shows the magnetic field is rather quiet and the plasma instrument indicates a change from energetic (few 100 eV) to low energy (few 10 eV) ions. T…

2009 Annales Geophysicae
VenusExpress 18
MHD aspect of current sheet oscillations related to magnetic field gradients
DOI: 10.5194/angeo-27-417-2009 Bibcode: 2009AnGeo..27..417E

Kubyshkin, I. V.; Semenov, V. S.; Erkaev, N. V. +2 more

One-fluid ideal MHD model is applied for description of current sheet flapping disturbances appearing due to a gradient of the normal magnetic field component. The wave modes are studied which are associated to the flapping waves observed in the Earth's magnetotail current sheet. In a linear approximation, solutions are obtained for model profiles…

2009 Annales Geophysicae
Cluster 18
Titan's plasma environment during a magnetosheath excursion: Real-time scenarios for Cassini's T32 flyby from a hybrid simulation
DOI: 10.5194/angeo-27-669-2009 Bibcode: 2009AnGeo..27..669S

Coates, A. J.; Dougherty, M. K.; Saur, J. +5 more

With a Saturnian magnetopause average stand-off distance of about 21 planetary radii, Titan spends most of its time inside the rotating magnetosphere of its parent planet. However, when Saturn's magnetosphere is compressed due to high solar wind dynamic pressure, Titan can cross Saturn's magnetopause in the subsolar region of its orbit and therefo…

2009 Annales Geophysicae
Cassini 18
Magnetic field and electric currents in the vicinity of polar cusps as inferred from Polar and Cluster data
DOI: 10.5194/angeo-27-1573-2009 Bibcode: 2009AnGeo..27.1573T

Tsyganenko, N. A.

A detailed statistical study of the magnetic structure of the dayside polar cusps is presented, based on multi-year sets of magnetometer data of Polar and Cluster spacecraft, taken in 1996-2006 and 2001-2007, respectively. Thanks to the dense data coverage in both Northern and Southern Hemispheres, the analysis spanned nearly the entire length of …

2009 Annales Geophysicae
Cluster 18
Magnetosheath cavities: case studies using Cluster observations
DOI: 10.5194/angeo-27-3765-2009 Bibcode: 2009AnGeo..27.3765K

Dandouras, I.; Kaymaz, Z.; Sibeck, D. G. +1 more

This paper presents examples of magnetosheath cavities in Cluster spacecraft observations. The cavities are accompanied by high energy particles in the magnetosheath and characterized by depressed magnetic fields and densities. Flow speeds decrease and temperatures increase within the cavities. All magnetosheath parameters show increased variabili…

2009 Annales Geophysicae
Cluster 17
Spatial aliasing and distortion of energy distribution in the wave vector domain under multi-spacecraft measurements
DOI: 10.5194/angeo-27-3031-2009 Bibcode: 2009AnGeo..27.3031N

Glassmeier, K. -H.; Narita, Y.

Aliasing is a general problem in the analysis of any measurements that make sampling at discrete points. Sampling in the spatial domain results in a periodic pattern of spectra in the wave vector domain. This effect is called spatial aliasing, and it is of particular importance for multi-spacecraft measurements in space. We first present the theor…

2009 Annales Geophysicae
Cluster 17
Field line distribution of density at L=4.8 inferred from observations by CLUSTER
DOI: 10.5194/angeo-27-705-2009 Bibcode: 2009AnGeo..27..705D

Kistler, L. M.; Mouikis, C.; Décréau, P. +8 more

For two events observed by the CLUSTER spacecraft, the field line distribution of mass density ρ was inferred from Alfvén wave harmonic frequencies and compared to the electron density ne from plasma wave data and the oxygen density nO+ from the ion composition experiment. In one case, the average ion mass M≈ρ/ne w…

2009 Annales Geophysicae
Cluster 16
Shape, size, velocity and field-aligned currents of dayside plasma injections: a multi-altitude study
DOI: 10.5194/angeo-27-1251-2009 Bibcode: 2009AnGeo..27.1251M

Pitout, F.; Fazakerley, A. N.; Dunlop, M. W. +3 more

On 20 February 2005, Cluster in the outer magnetosphere and Double Star-2 (TC-2) at mid-altitude are situated in the vicinity of the northern cusp/mantle, with Cluster moving sunward and TC-2 anti-sunward. Their magnetic footprints come very close together at about 15:28 UT, over the common field-of-view of SuperDARN radars. Thanks to this conjunc…

2009 Annales Geophysicae
Cluster DoubleStar 16