Search Publications

Data Mining Reconstruction of Magnetotail Reconnection and Implications for Its First-Principle Modeling

Sitnov, Mikhail; Stephens, Grant; Motoba, Tetsuo +1 more

Magnetic reconnection is a fundamental process providing topological changes of the magnetic field, reconfiguration of space plasmas and release of energy in key space weather phenomena, solar flares, coronal mass ejections and magnetospheric substorms. Its multiscale nature is difficult to study in observations because of their sparsity. Here we …

Concurrent empirical magnetic reconstruction of storm and substorm spatial scales using data mining and virtual spacecraft

Stephens, Grant K.; Sitnov, Mikhail I.

Data-mining (DM) has ushered in a new era of empirical magnetic reconstructions of the 4 magnetosphere via application of the k-nearest neighbors (kNN) method. In this approach, 5 the combined magnetosphere storm-substorm state is characterized by the Sym-H and AL IMF 6 indices, their time derivatives, and the solar wind electric field vBz . Howev…

Kelvin-Helmholtz Instability Associated with Reconnection and Ultra Low Frequency Waves at the Ground: A Case Study

Grigorenko, E. E.; Kronberg, E. A.; Nykyri, K. +7 more

The Kelvin-Helmholtz instability (KHI) and its effects relating to the transfer of energy and mass from the solar wind into the magnetosphere remain an important focus of magnetospheric physics. One such effect is the generation of Pc4-Pc5 ultra low frequency (ULF) waves (periods of 45-600 s). On 3 July 2007 at ~0500 magnetic local time the Cluste…

On the Origin of High–Frequency Magnetic Fluctuations in the Interplanetary Medium: A Brownian–like Approach

Vecchio, Antonio; Chiappetta, Federica; Lepreti, Fabio +2 more

Low–frequency fluctuations in the interplanetary medium have been extensively investigated and described in the framework of turbulence, and the observed universal scaling behavior represents a clear signature of the underlying energy cascade. On the contrary, the interpretation of observations of plasma fluctuations at high frequencies, where wav…

High-latitude cold ion outflow inferred from the Cluster wake observations in the magnetotail lobes and the polar cap region

André, Mats; Li, Kun; Wei, Yong +3 more

Cold ions with low (a few eV) thermal energies and also often low bulk drift energies, dominate the ion population in the Earth's magnetosphere. These ions mainly originate from the ionosphere. Here we concentrate on cold ions in the high latitude polar regions, where magnetic field lines are open and connected to the magnetotail. Outflow from the…