Search Publications
Quadratic Magnetic Gradients From Seven- And Nine-Spacecraft Constellations
Shen, Chao; Kieokaew, Rungployphan; Zeng, Gang +1 more
To uncover the dynamics of magnetized plasma, it is crucial to determine the geometric structure of the magnetic field, which depends on its linear and quadratic spatial gradients. Estimating the linear magnetic gradient requires at least 4 simultaneous magnetic measurements, while calculating the quadratic gradients generally requires at least 10…
Investigation Of The Occurrence Of Significant Deviations In The Magnetopause Location: Solar-Wind And Foreshock Effects
Plaschke, Ferdinand; Grimmich, Niklas; Pöppelwerth, Adrian +7 more
Common magnetopause models can predict the location of the magnetopause with respect to upstream conditions from different sets of input parameters, including solar-wind pressure and the interplanetary magnetic field. However, recent studies have shown that some effects of upstream conditions may still be poorly understood since deviations between…
Estimating Gradients Of Physical Fields In Space
Shen, Chao; Zhou, Yufei
This study focuses on the development of a multi-point technique for future constellation missions, aiming to measure gradients at various orders, in particular the linear and quadratic gradients, of a general field. It is well established that, in order to estimate linear gradients, the spacecraft must not lie on a plane. Through analytical explo…
Does High-Latitude Ionospheric Electrodynamics Exhibit Hemispheric Mirror Symmetry?
Hatch, Spencer Mark; Vanhamäki, Heikki; Magnus Laundal, Karl +6 more
Ionospheric electrodynamics is a problem of mechanical stress balance mediated by electromagnetic forces. Joule heating (the total rate of frictional heating of thermospheric gases and ionospheric plasma) and ionospheric Hall and Pedersen conductances comprise three of the most basic descriptors of this problem. More than half a century after iden…
The Cluster Spacecrafts' View Of The Motion Of The High-Latitude Magnetopause
Darrouzet, Fabien; Plaschke, Ferdinand; Grimmich, Niklas +10 more
The magnetopause is the boundary between the interplanetary magnetic field and the terrestrial magnetic field. It is influenced by different solar-wind conditions, which lead to a change in the shape and location of the magnetopause. The interaction between the solar wind and the magnetosphere can be studied from in situ spacecraft observations. M…
Scalar-Potential Mapping Of The Steady-State Magnetosheath Model
Toepfer, Simon; Narita, Yasuhito; Schmid, Daniel
The steady-state magnetosheath model has various applications for studying the plasma and magnetic field profile around the planetary magnetospheres. In particular, the magnetosheath model is analytically obtained by solving the Laplace equation for parabolic boundaries (bow shock and magnetopause). We address the question, how can we utilize the …
Local bow shock environment during magnetosheath jet formation: results from a hybrid-Vlasov simulation
Pfau-Kempf, Yann; Ganse, Urs; Battarbee, Markus +11 more
Magnetosheath jets are plasma structures that are characterised by enhanced dynamic pressure and/or plasma velocity. In this study, we investigate the formation of magnetosheath jets in four two-dimensional simulation runs of the global magnetospheric hybrid-Vlasov model Vlasiator. We focus on jets whose origins were not clearly determined in a pr…
Concerning the detection of electromagnetic knot structures in space plasmas using the wave telescope technique
Motschmann, Uwe; Glassmeier, Karl-Heinz; Toepfer, Simon
The wave telescope technique is broadly established in the analysis of spacecraft data and serves as a bridge between local measurements and the global picture of spatial structures. The technique is originally based on plane waves and has been extended to spherical waves, phase-shifted waves and planetary magnetic field representation. The goal o…
The m-dimensional spatial Nyquist limit using the wave telescope for larger numbers of spacecraft
Motschmann, Uwe; Plaschke, Ferdinand; Glassmeier, Karl-Heinz +2 more
Spacecraft constellations consisting of multiple satellites are becoming more and more interesting not only for commercial use but also for space science missions. The proposed and accepted scientific multi-satellite missions that will operate within Earth's magnetospheric environment, like HelioSwarm, require researchers to extend established met…
Velocity of magnetic holes in the solar wind from Cluster multipoint measurements
Raptis, Savvas; Karlsson, Tomas; Trollvik, Henriette
We present the first statistical study on the velocity of magnetic holes (MHs) in the solar wind. Magnetic holes are localized depressions of the magnetic field, often divided into two classes: rotational and linear MHs. We have conducted a timing analysis of observations of MHs from the Cluster mission in the first quarter of 2005. In total, 69 e…