Search Publications
DC and low-frequency double probe electric field measurements in space
Mozer, F. S.
The double probe technique for measuring DC and low-frequency electric fields in space plasmas is described with an emphasis on uncertainties in the measurements, data analysis techniques, and methods for improving the electric field measurements in future missions.
Reconnection events in Saturn's magnetotail: Dependence of plasmoid occurrence on planetary period oscillation phase
Jackman, C. M.; Cowley, S. W. H.; Provan, G.
During its exploration of Saturn's magnetotail the Cassini magnetometer has detected many in situ examples of magnetic reconnection, in the form of plasmoids, traveling compression regions (TCRs), and dipolarizations. Meanwhile, many magnetospheric phenomena have been shown to be organized with particular regularity by planetary period oscillation…
Auroral evidence of radial transport at Jupiter during January 2014
Gray, R. L.; Badman, S. V.; Bonfond, B. +5 more
We present Jovian auroral observations from the 2014 January Hubble Space Telescope (HST) campaign and investigate the auroral signatures of radial transport in the magnetosphere alongside contemporaneous radio and Hisaki EUV data. HST FUV auroral observations on day 11 show, for the first time, a significantly superrotating polar spot poleward of…
Global magnetohydrodynamic simulation of the 15 March 2013 coronal mass ejection event—Interpretation of the 30-80 MeV proton flux
Wu, S. T.; Vourlidas, Angelos; Wu, Chin-Chun +4 more
The coronal mass ejection (CME) event on 15 March 2013 is one of the few solar events in Cycle 24 that produced a large solar energetic particle (SEP) event and severe geomagnetic activity. Observations of SEP from the ACE spacecraft show a complex time-intensity SEP profile that is not easily understood with current empirical SEP models. In this …
Ionospheric loss from Mars as predicted by hybrid particle simulations
Brecht, Stephen H.; Ledvina, Stephen A.; Bougher, Stephen W.
This paper reports the results of hybrid simulations of the Mars-solar wind interaction. The focus is on the loss rates of O+ and O2+ from the Martian ionosphere while examining the importance of including 3-D dimensional neutral atmospheres with their associated neutral winds. The simulation loss rates are found t…
A survey of superthermal electron flux depressions, or "electron holes," within the illuminated Martian induced magnetosphere
Fränz, M.; Lester, M.; Andrews, D. J. +4 more
Since Mars lacks a global intrinsic magnetic field, the solar wind interacts directly with the Martian upper atmosphere and ionosphere. The presence of localized intense remnant crustal magnetic fields adds to this interaction, making the Martian plasma system a unique environment within the solar system. Rapid reductions in the electron flux, ref…
Oxygen impacts on dipolarization fronts and reconnection rate
Lapenta, Giovanni; Walker, Raymond J.; Ashour-Abdalla, Maha +1 more
Spacecraft observations near a magnetotail X line show that oxygen (O+) ions are minor species during nonstorm substorms, but they can become major species during some of the storm time substorms. Dipolarization fronts (DFs), which are characterized by a sharp increase northward magnetic field in the magnetotail, are commonly observed d…
Ion nose spectral structures observed by the Van Allen Probes
Kistler, L. M.; Zhang, J. -C.; Spence, H. E. +5 more
We present a statistical study of nose-like structures observed in energetic hydrogen, helium, and oxygen ions near the inner edge of the plasma sheet. Nose structures are spectral features named after the characteristic shapes of energy bands or gaps in the energy-time spectrograms of in situ measured ion fluxes. Using 22 months of observations f…
Interactions between magnetosonic waves and ring current protons: Gyroaveraged test particle simulations
Zhang, Hui; Huang, Shiyong; Fu, Song +6 more
Gyroaveraged test particle simulations are implemented to quantitatively investigate interactions between linearly polarized magnetosonic waves (i.e., equatorial noises) and ring current protons inside and outside the plasmasphere at L = 4.5. For magnetosonic waves at the frequency of 33.3 Hz (fw/fcp = 6.4 at the magnetic equ…
Influence of intermittency on the anisotropy of magnetic structure functions of solar wind turbulence
He, Jiansen; Wang, Xin; Wang, Linghua +4 more
Intermittency appears to be connected with the spectral anisotropy of solar wind turbulence. We use the Local Intermittency Measure to identify and remove intermittency from the magnetic field data measured by the Ulysses spacecraft in fast solar wind. Structure functions are calculated based on the time sequences as obtained before and after remo…