Search Publications
Atmospheric loss from the dayside open polar region and its dependence on geomagnetic activity: implications for atmospheric escape on evolutionary timescales
Nilsson, Hans; Dandouras, Iannis; Slapak, Rikard +3 more
We have investigated the total O+ escape rate from the dayside open polar region and its dependence on geomagnetic activity, specifically Kp. Two different escape routes of magnetospheric plasma into the solar wind, the plasma mantle, and the high-latitude dayside magnetosheath have been investigated separately. The flux of O+
Tail reconnection in the global magnetospheric context: Vlasiator first results
Pulkkinen, Tuija I.; Vainio, Rami; Juusola, Liisa +7 more
The key dynamics of the magnetotail have been researched for decades and have been associated with either three-dimensional (3-D) plasma instabilities and/or magnetic reconnection. We apply a global hybrid-Vlasov code, Vlasiator, to simulate reconnection self-consistently in the ion kinetic scales in the noon-midnight meridional plane, including b…
Relative outflow enhancements during major geomagnetic storms - Cluster observations
Nilsson, Hans; Slapak, Rikard; Schillings, Audrey +2 more
The rate of ion outflow from the polar ionosphere is known to vary by orders of magnitude, depending on the geomagnetic activity. However, the upper limit of the outflow rate during the largest geomagnetic storms is not well constrained due to poor spatial coverage during storm events. In this paper, we analyse six major geomagnetic storms between…
Quantification of the total ion transport in the near-Earth plasma sheet
Karlsson, Tomas; Nilsson, Hans; Slapak, Rikard +4 more
Recent studies strongly suggest that a majority of the observed O+ cusp outflows will eventually escape into the solar wind, rather than be transported to the plasma sheet. Therefore, an investigation of plasma sheet flows will add to these studies and give a more complete picture of magnetospheric ion dynamics. Specifically, it will pr…
Absence of the strahl during times of slow wind
Goldstein, Melvyn L.; Gurgiolo, Chris
It is not uncommon during periods when the solar wind speed is less than 425 km s-1 to observe near 1 AU no evidence of a strahl population in either the electron solar wind or within the foreshock. Estimating the fluid flow within each energy step returned from the Plasma Electron And Current Experiment (PEACE) on board Cluster-2 often…
Occurrence rate of dipolarization fronts in the plasma sheet: Cluster observations
Plaschke, Ferdinand; Zhang, Tielong; Volwerk, Martin +6 more
We investigate the occurrence rate of dipolarization fronts (DFs) in the plasma sheet by taking full advantage of all four Cluster satellites (C1-4) from years 2001 to 2009. In total, we select 466 joint-observation DF events, in which 318, 282, 254, and 236 DFs are observed by C1, C2, C3, and C4, respectively. Our findings are as follows: (1) the…
Magnetic reconnection during steady magnetospheric convection and other magnetospheric modes
Cowley, Stanley W. H.; Gérard, Jean-Claude; Hubert, Benoit +1 more
We use remote sensing of the proton aurora with the IMAGE-FUV SI12 (Imager for Magnetopause to Aurora Global Exploration-Far Ultraviolet-Spectrographic Imaging at 121.8 nm) instrument and radar measurements of the ionospheric convection from the SuperDARN (Super Dual Aurora Radar Network) facility to estimate the open magnetic flux in the Earth's …
Global geomagnetic responses to the IMF Bz fluctuations during the September/October 2003 high-speed stream intervals
Echer, Ezequiel; Korth, Axel; José Alves Bolzan, Mauricio +1 more
In this paper, we follow the coupling from the solar wind to the Earth's magnetotail, geosynchronous orbit, auroral zone and to the ground, during periods of Alfvénic fluctuations in high-speed solar wind streams (HSSs) and their corotating interaction regions (CIRs). We employ cross-wavelet analysis of magnetic field, particle flux and auroral el…
Statistical survey of day-side magnetospheric current flow using Cluster observations: magnetopause
Fornaçon, Karl-Heinz; Glassmeier, Karl-Heinz; Liebert, Evelyn +2 more
We present a statistical survey of current structures observed by the Cluster spacecraft at high-latitude day-side magnetopause encounters in the close vicinity of the polar cusps. Making use of the curlometer technique and the fluxgate magnetometer data, we calculate the 3-D current densities and investigate the magnetopause current direction, lo…