Search Publications
GUMICS-4 analysis of interplanetary coronal mass ejection impact on Earth during low and typical Mach number solar winds
Pulkkinen, Tuija I.; Raukunen, Osku; Dimmock, Andrew P. +5 more
We study the response of the Earth's magnetosphere to fluctuating solar wind conditions during interplanetary coronal mass ejections (ICMEs) using the Grand Unified Magnetosphere-Ionosphere Coupling Simulation (GUMICS-4). The two ICME events occurred on 15-16 July 2012 and 29-30 April 2014. During the strong 2012 event, the solar wind upstream val…
Low-frequency magnetic variations at the high-β Earth bow shock
Petrukovich, Anatoli A.; Chugunova, Olga M.; Shustov, Pavel I.
Observations of Earth's bow shock during high-β (ratio of thermal to magnetic pressure) solar wind streams are rare. However, such shocks are ubiquitous in astrophysical plasmas. Typical solar wind parameters related to high β (here β>10) are as follows: low speed, high density, and a very low interplanetary magnetic field of 1-2 nT. These cond…
Reflection of the strahl within the foot of the Earth's bow shock
Goldstein, Melvyn L.; Gurgiolo, Christopher A.; Viñas, Adolfo
The reflection of a fraction of the solar wind at the bow shock to some extent defines the physical properties of what is known as the foreshock, the region where the interplanetary magnetic field has a direct connection to the bow shock. Both ion and electron reflection have been observed and together form a significant source of free energy that…
Signatures of red-shifted foot points in the quiescent coronal loop system
Rao, Yamini K.; Srivastava, Abhishek K.; Kayshap, Pradeep +1 more
We observed quiescent coronal loops using multi-wavelength observations from the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory (SDO) on 13 April 2016. The flows at the foot points of such loop systems are studied using spectral data from the Interface Region Imaging Spectrograph (IRIS). The Doppler velocity distributions…
Strong southward and northward currents observed in the inner plasma sheet
Shen, Chao; Ji, Yong; Yang, Yan-Yan
It is generally believed that field-aligned currents (FACs) and the ring current (RC) are two dominant parts of the inner magnetosphere. However, using the Cluster spacecraft crossing the pre-midnight inner plasma sheet in the latitudinal region between 10 and 30∘ N, it is found that, during intense geomagnetic storms, in addition to FA…
Magnetosheath jet properties and evolution as determined by a global hybrid-Vlasov simulation
Kajdič, Primož; Blanco-Cano, Xóchitl; Karlsson, Tomas +9 more
We use a global hybrid-Vlasov simulation for the magnetosphere, Vlasiator, to investigate magnetosheath high-speed jets. Unlike many other hybrid-kinetic simulations, Vlasiator includes an unscaled geomagnetic dipole, indicating that the simulation spatial and temporal dimensions can be given in SI units without scaling. Thus, for the first time, …
Contrasting dynamics of electrons and protons in the near-Earth plasma sheet during dipolarization
Grigorenko, Elena E.; Kronberg, Elena A.; Daly, Patrick W. +4 more
The fortunate location of Cluster and the THEMIS P3 probe in the near-Earth plasma sheet (PS) (at X ∼ -7-9 RE) allowed for the multipoint analysis of properties and spectra of electron and proton injections. The injections were observed during dipolarization and substorm current wedge formation associated with braking of multiple bursty…
Turbulent processes in the Earth's magnetotail: spectral and statistical research
Grigorenko, Elena E.; Kronberg, Elena A.; Kozak, Liudmyla V. +3 more
We use the magnetic field measurements from four spacecraft of the Cluster-II mission (three events from 2005 to 2015) for the analysis of turbulent processes in the Earth's magnetotail. For this study we conduct the spectral, wavelet and statistical analysis. In the framework of statistical examination, we determine the kurtosis for selected even…
Cavitons and spontaneous hot flow anomalies in a hybrid-Vlasov global magnetospheric simulation
Jarvinen, Riku; Vainio, Rami; Dimmock, Andrew P. +12 more
In this paper we present the first identification of foreshock cavitons and the formation of spontaneous hot flow anomalies (SHFAs) with the Vlasiator global magnetospheric hybrid-Vlasov simulation code. In agreement with previous studies we show that cavitons evolve into SHFAs. In the presented run, this occurs very near the bow shock. We report …
Fast plasma sheet flows and X line motion in the Earth's magnetotail: results from a global hybrid-Vlasov simulation
Jarvinen, Riku; Juusola, Liisa; Pfau-Kempf, Yann +6 more
Fast plasma flows produced as outflow jets from reconnection sites or X lines are a key feature of the dynamics in the Earth's magnetosphere. We have used a polar plane simulation of the hybrid-Vlasov model Vlasiator, driven by steady southward interplanetary magnetic field and fast solar wind, to study fast plasma sheet ion flows and related magn…