Search Publications
Dissecting Earth's Magnetosphere: 3D Energy Transport in a Simulation of a Real Storm Event
Toth, G.; Pulkkinen, T. I.; Brenner, A. +1 more
We present new analysis methods of 3D MHD output data from the Space Weather Modeling Framework during a simulated storm event. Earth's magnetosphere is identified in the simulation domain and divided based on magnetic topology and the bounding magnetopause definition. Volume energy contents and surface energy fluxes are analyzed for each subregio…
Comparative Solar Minima Using the McIntosh Archive
Gibson, Sarah E.; Webb, David F.; Hewins, Ian M. +3 more
The McIntosh Archive consists of four solar cycles (SC20-23) of synoptic maps of solar features (magnetic polarities, coronal holes, filaments, sunspots, plage) that were produced by Patrick McIntosh and his cartographers. In this paper we present the full Archive for the first time and find a hemispheric pattern of coronal hole polarity reflectin…
Multipoint Observations of Dispersive Scale Alfvénic Field-Line Resonances Associated With Substorm Auroral Beads
Frey, Harald U.; Wing, Simon; Chaston, Christopher C. +2 more
We present a case study of the field-aligned current (FAC) systems that transpire within the high-altitude auroral acceleration region of an "auroral bead" initiated double oval substorm observed on 23 February 2001 by the Cluster fleet. Conjunctive Cluster measurements and auroral images from IMAGE reveal that auroral bead current system formatio…
Characteristics of Magnetic Reconnection With a Finite X-Line Length
Lu, Quanming; Wang, Rongsheng; Lu, San +2 more
The characteristics of magnetic reconnection with a finite x-line length are studied using three-dimensional (3D) particle-in-cell (PIC) simulations. We simulate two cases: anti-parallel reconnection and guide field reconnection. In both cases, reconnection is triggered by an initial perturbation that is localized in the current direction, and the…
The Association of Cusp-Aligned Arcs With Plasma in the Magnetotail Implies a Closed Magnetosphere
Dandouras, I.; Anderson, B. J.; Fazakerley, A. N. +7 more
We investigate a 15-day period in October 2011. Auroral observations by the Special Sensor Ultraviolet Spectrographic Imager instrument onboard the Defense Meteorological Satellite Program F16, F17, and F18 spacecraft indicate that the polar regions were covered by weak cusp-aligned arc (CAA) emissions whenever the interplanetary magnetic field (I…
Indirect Observations of Electric Fields at Comet 67P
Gunell, H.; Nilsson, H.; Goetz, C. +2 more
No spacecraft visiting a comet has been equipped with instruments to directly measure the static electric field. However, the electric field can occasionally be estimated indirectly by observing its effects on the ion velocity distribution. We present such observations made by the Rosetta spacecraft on 19 April 2016, 35 km from the nucleus. At thi…
Local Electron Density Depletions in the Martian Upper Ionosphere Obtained From MARSIS: Comparison With ASPERA-3, and MAVEN, and the Connection With Crustal Magnetic Fields
Frahm, R. A.; Duru, F.; Hughes, D. +3 more
Steep electron density depletions in the Martian ionosphere are important, especially because they could be regions of significant plasma escape. Local electron density profiles of the Martian ionosphere obtained from the radar sounder onboard the Mars Express spacecraft often show large fluctuations. In some cases, these fluctuations are observed…
On Current Sheets and Associated Density Spikes in Titan's Ionosphere as Seen From Cassini
Edberg, Niklas J. T.; Vigren, Erik; Bertucci, Cesar +3 more
The Cassini spacecraft made in-situ measurements of Titan's plasma environment during 126 close encounters between 2004 and 2017. Here we report on observations from the Radio and Plasma Waves System/Langmuir probe instrument (RPWS/LP) from which we have observed, primarily on the outbound leg, a localized increase of the electron density by up to…
Space Weather Disturbances in Non-Stormy Times: Occurrence of dB/dt Spikes During Three Solar Cycles
Gunell, H.; Hamrin, M.; Opgenoorth, H. +8 more
Spatio-temporal variations of ionospheric currents cause rapid magnetic field variations at ground level and Geomagnetically Induced Currents (GICs) that can be harmful for human infrastructure. The risk for large excursions in the magnetic field time derivative, "dB/dt spikes", is known to be high during geomagnetic storms and substorms. However,…
Geocoronal Solar Wind Charge Exchange Process Associated With the 2006-December-13 Coronal Mass Ejection Event
Toriumi, Shin; Mitsuda, Kazuhisa; Yamasaki, Noriko Y. +1 more
We report the discovery of a geocoronal solar wind charge exchange (SWCX) event corresponding to the well-known 2006 December 13th coronal mass ejection (CME) event. Strong evidence for the charge exchange origin of this transient diffuse emission is provided by prominent non-thermal emission lines at energies of O7+, Ne9+, M…