Search Publications
Solar cycle dependence of the cusp O+ access to the near-Earth magnetotail
Dandouras, I.; Klecker, B.; Kistler, L. M. +2 more
Ionospheric origin O+ accelerated in the cusp/cleft region is one source for the O+ observed in the plasma sheet. This O+ is convected over the polar cap, flowing along open field lines to the tail lobes, and finally entering the plasma sheet. In this paper we use Cluster/CODIF data to study how the occurrence of c…
Energetic electron fluxes at Saturn from Cassini observations
Summers, Danny; Tang, Rongxin
Energetic electron fluxes (18 keV-21 MeV) observed by the MIMI/LEMMS instrument on the Cassini mission during 2004 to 2008 are analyzed. We consider all 101 orbits and we select portions of the orbits that lie within 0.5 RS of the magnetic equatorial plane, where RS is Saturn's radius. We determine the average electron differ…
Changes in the magnetotail configuration before near-Earth reconnection
Gordeev, E. I.; Snekvik, K.; Østgaard, N. +4 more
We have examined three typical substorm growth phase signatures in the magnetotail two hours before near Earth reconnection; namely current sheet thinning, field line stretching and increase in the lobe magnetic pressure. The reconnection events were identified from in situ measurements in the plasma sheet by the Cluster spacecraft. The events wer…
Understanding shock dynamics in the inner heliosphere with modeling and Type II radio data: The 2010-04-03 event
St. Cyr, O. C.; Odstrcil, D.; Gopalswamy, N. +3 more
The 2010 April 03 solar event was studied using observations from STEREO SECCHI, SOHO LASCO, and Wind kilometric Type II data (kmTII) combined with WSA-Cone-ENLIL model simulations performed at the Community Coordinated Modeling Center (CCMC). In particular, we identified the origin of the coronal mass ejection (CME) using STEREO EUVI and SOHO EIT…
Dynamics of long-period ULF waves in the plasma sheet: Coordinated space and ground observations
Zhang, T. L.; Nakamura, R.; Baumjohann, W. +11 more
Spacecraft and ground-based observations are used to study characteristics of ultralow frequency waves in the plasma sheet from the postmidnight to morning local time sectors in the terrestrial magnetosphere. Field line resonance (FLR) type oscillations with discrete and latitude-dependent frequencies in the ranges of 1.7-2.0 and 3.0-3.2 mHz are o…
Cassini observations of ionospheric photoelectrons at large distances from Titan: Implications for Titan's exospheric environment and magnetic tail
Lewis, G. R.; Coates, A. J.; Jones, G. H. +6 more
Discrete peaks near 24.1 eV are seen in electron spectra measured in Titan's ionosphere by the ELS (Electron Spectrometer), part of the Cassini Plasma Spectrometer (CAPS), and are interpreted as photoelectrons. These photoelectrons are generated as a result of ionization of N2 by the strong solar He II (30.4 nm) line. They are generally…
Pickup protons: Comparisons using the three-dimensional MHD HHMS-PI model and Ulysses SWICS measurements
Sun, Wei; Intriligator, Devrie S.; Detman, Thomas +5 more
We report the first comparisons of pickup proton simulation results with in situ measurements of pickup protons obtained by the SWICS instrument on Ulysses. Simulations were run using the three dimensional (3D) time-dependent Hybrid Heliospheric Modeling System with Pickup Protons (HHMS-PI). HHMS-PI is an MHD solar wind model, expanded to include …
Saturn's auroral/polar H3+ infrared emission: The effect of solar wind compression
Dougherty, Michele K.; Bunce, Emma J.; Melin, Henrik +6 more
Previous investigations into Saturn's aurora have shown that they are strongly controlled by the solar wind. Here, for the first time, we use a combination of ground-based infrared observations of the aurora and in situ measurements of the magnetosphere in order to better understand this association. We show that large-scale variability in both th…
The role of the inner tail to midtail plasma sheet in channeling solar wind power to the ionosphere
Dandouras, I.; André, M.; Hamrin, M. +5 more
In this article we use Cluster power density (E · J) data from 2001, 2002, and 2004 to investigate energy conversion and transfer in the plasma sheet. We show that a southward IMF Bz is favorable for plasma sheet energy conversion, and that there is an increased particle and Poynting flux toward the Earth at times when Cluster observes …
Geometry of the 20 November 2003 magnetic cloud
Park, Sung-Hong; Cho, Kyung-Suk; Kim, Yeon-Han +2 more
This study is an attempt to find a coherent interpretation of the link between the 20 November 2003 magnetic cloud (MC) and its solar source. Most previous studies agree on the orientation of the MC, but the orientation is nearly perpendicular to the axis of the post-eruption arcade (PEA) or the orientation of the neutral line in the solar source …