Search Publications
Variation in the Pedersen Conductance Near Jupiter's Main Emission Aurora: Comparison of Hubble Space Telescope and Galileo Measurements
Nichols, J. D.; Vogt, M. F.; Rutala, M. J. +1 more
We present the first large-scale statistical survey of the Jovian main emission (ME) to map auroral properties from their ionospheric locations out into the equatorial plane of the magnetosphere, where they are compared directly to in-situ spacecraft measurements. We use magnetosphere-ionosphere (MI) coupling theory to calculate currents from the …
Parallel Electron Beams at Io: Numerical Simulations of the Dense Plasma Wake
Bagenal, F.; Dols, V.; Paterson, W. R.
In 1995, the Galileo spacecraft traversed the wake of Io at ∼900 km altitude. The instruments onboard detected intense bi-directional field-aligned electron beams (∼140 eV-150 keV), embedded in a dense, cold and slow plasma wake (Nel ∼ 35,000 cm−3, Ti < 10 eV, V < 3 km/s). Similar electron beams were also det…
The April 2023 SYM-H = −233 nT Geomagnetic Storm: A Classical Event
Henri, Pierre; Hajra, Rajkumar; Horne, Richard B. +8 more
The 23-24 April 2023 double-peak (SYM-H intensities of −179 and −233 nT) intense geomagnetic storm was caused by interplanetary magnetic field southward component Bs associated with an interplanetary fast-forward shock-preceded sheath (Bs of 25 nT), followed by a magnetic cloud (MC) (Bs of 33 nT), respectively. The…
Source of the Observed Enhancements in Thermospheric ΣO/N2 During Two Solar Eclipses in 2023
Zhang, Y.; Cantrall, C. E.; Mrak, S. +4 more
Two solar eclipse events in 2023 appeared to produce considerable enhancements in the thermospheric column density ratio of monatomic oxygen to molecular nitrogen (ΣO/N2) as measured by TIMED GUVI. We quantify potential sources for eclipse-induced ΣO/N2 changes and find that the observed enhancements arise from the ionospheri…
On the Contribution of Latitude-Dependent ULF Waves to the Radial Transport of Off-Equatorial Relativistic Electrons in the Radiation Belts
Angelopoulos, Vassilis; Li, Xinlin; Ergun, Robert E. +15 more
Ultra-low frequency (ULF) waves radially diffuse hundreds-keV to few-MeV electrons in the magnetosphere, as the range of drift frequencies of such electrons overlaps with the wave frequencies, leading to resonant interactions. Theoretically this process is described by analytic expressions of the resonant interactions between electrons and ULF wav…
Deep Entry of Low-Energy Ions Into Mercury's Magnetosphere: BepiColombo Mio's Third Flyby Observations
Persson, Moa; Saito, Yoshifumi; Delcourt, Dominique +15 more
Although solar wind-driven convection is expected to dominate magnetospheric circulation at Mercury, its exact pattern remains poorly characterized by observations. Here we present BepiColombo Mio observations during the third Mercury flyby indicative of convection-driven transport of low-energy dense ions into the deep magnetosphere. During the f…
Magnetic Field in the Earth's Magnetosheath: Models Versus Observations
Vandas, M.; Romashets, E.
Magnetic field measurements in the Earth's magnetosheath are compared with four analytical models, namely Kobel and Flückiger (1994), (https://doi.org/10.1029/94ja01778), Romashets and Vandas (2019), (https://doi.org/10.1029/2018ja026006), Vandas and…
Suprathermal Outflowing H+ Ions in the Lobe Driven by an Interplanetary Shock: 1. An Observation Event
Mouikis, C. G.; Wang, Chih-Ping; Wang, Xueyi +2 more
To better understand how sharp changes in the solar wind and interplanetary magnetic field conditions affect the ionosphere outflows at high latitudes, we analyze an event observed on 17 July 2002 showing suprathermal (tens to hundreds of eV) outflowing H+ ions in the lobe driven by the impact of an interplanetary (IP) shock. A spacecra…
Revised Magnetospheric Model Reveals Signatures of Field-Aligned Current Systems at Mercury
Plaschke, Ferdinand; Exner, W.; Heyner, D. +2 more
Mercury is the smallest and innermost planet of our solar system and has a dipole-dominated internal magnetic field that is relatively weak, very axisymmetric and significantly offset toward north. Through the interaction with the solar wind, a magnetosphere is created. Compared to the magnetosphere of Earth, Mercury's magnetosphere is smaller and…
Stream Interaction Regions in the Minimum of Solar Cycles 23 and 24
Aguilar-Rodriguez, E.; Corona-Romero, P.; Gonzalez-Esparza, J. A. +1 more
Stream interaction regions (SIRs) dominate the large-scale solar wind dynamics during the minimum of the solar cycle. The interaction of SIRs with the magnetosphere causes most of geomagnetic storms during this epoch. We used in-situ solar wind observations at 1 AU to study 62 SIRs detected in the interval 2007-2008 (minimum of cycle 23) and 61 SI…