Search Publications
A statistical study on hot flow anomaly current sheets
Zhao, L. L.; Zhang, H.; Zong, Q. -G.
Hot flow anomalies (HFAs) are phenomena frequently observed near Earth's bow shock and form when the interplanetary discontinuities interact with Earth's bow shock. We perform a statistical study to determine what kind of discontinuities are more efficient to generate HFAs. We use strict criteria to identify classic HFAs, excluding similar foresho…
High-latitude Pi2 pulsations associated with kink-like neutral sheet oscillations
Zhang, T. L.; Volwerk, M.; Wang, G. Q. +2 more
A kink-like neutral sheet oscillation event observed by Cluster between 1436 and 1445 UT on 15 October 2004 has been investigated. The oscillations with periods between 40 and 60 s, observed at (-13.1, 8.7, -0.5) RE, are dominant in BX and BY. And they propagate mainly duskward with a velocity of (86, 147, 46) km/s…
The dependence of magnetospheric plasma mass loading on geomagnetic activity using Cluster
Dandouras, I.; Sandhu, J. K.; Yeoman, T. K. +2 more
Understanding changes in the magnetospheric mass density during disturbed geomagnetic conditions provides valuable insight into the dynamics and structure of the environment. The mass density plays a significant role in a variety of magnetospheric processes, such as wave propagation, magnetic reconnection rates, and radiation belt dynamics. In thi…
Dayside and nightside magnetic field responses at 780 km altitude to dayside reconnection
Snekvik, K.; Østgaard, N.; Tenfjord, P. +4 more
During southward interplanetary magnetic field, dayside reconnection will drive the Dungey cycle in the magnetosphere, which is manifested as a two-cell convection pattern in the ionosphere. We address the response of the ionospheric convection to changes in the dayside reconnection rate by examining magnetic field perturbations at 780 km altitude…
The parameterization of wave-particle interactions in the Outer Radiation Belt
Forsyth, C.; Rae, I. J.; Murphy, K. R. +3 more
We explore the use of mean value empirical wave models in diffusion models of the Outer Radiation Belt. We show that magnetospheric wave power is not normally distributed in time and that geomagnetic activity does not provide a deterministic proxy for the temporal variability of wave activity. Our findings indicate that current diffusion models si…
IUVS echelle-mode observations of interplanetary hydrogen: Standard for calibration and reference for cavity variations between Earth and Mars during MAVEN cruise
Bertaux, Jean-Loup; Chaufray, Jean-Yves; Stewart, Ian +11 more
The high-resolution echelle mode of the Imaging Ultraviolet Spectrograph (IUVS) instrument on the Mars Atmosphere and Volatile Evolution mission has been designed to measure D and H Lyman α emissions from the Martian atmosphere to obtain key information about the physical processes by which water escapes into space. Toward this goal, the absolute …
Electron heating and energy inventory during asymmetric reconnection in a laboratory plasma
Roytershteyn, V.; Chen, Li-Jen; Ji, Hantao +6 more
Electron heating and the energy inventory during asymmetric reconnection are studied in the laboratory plasma with a density ratio of about 8 across the current sheet. Features of asymmetric reconnection such as the large density gradients near the low-density side separatrices, asymmetric in-plane electric field, and bipolar out-of-plane magnetic…
Electron temperature anisotropy regulation by whistler instability
Yoon, P. H.; Hwang, J.; Kim, H. P. +1 more
The solar wind electron temperature anisotropy is regulated by a number of physical processes, which include adiabatic expansion, electron Coulomb collisions, and microinstabilities. In the collisionless limit, the measured electron temperature anisotropy is constrained by the marginal threshold conditions for whistler (electromagnetic electron cy…
Phase relationship between ULF waves and drift-bounce resonant ions: A statistical study
Zong, Q. G.; Rankin, R.; Wang, Y. F. +4 more
We explore the phase relationship between the poloidal mode ULF wave electric field oscillations and drift-bounce resonant oxygen ions under the resonant condition of N = 2 at the magnetic equator. Using Cluster data from 2001 to 2004, we identify 55 fundamental poloidal mode wave events, among which 42 show "negative slope" pitch angle dispersion…
Long-Term Variability of Jupiter's Magnetodisk and Implications for the Aurora
Bunce, Emma J.; Clarke, John T.; Vogt, Marissa F. +2 more
Observations of Jupiter's UV auroral emissions collected over several years show that the ionospheric positions of the main emission and the Ganymede footprint can vary by as much as 3° in latitude. One explanation for this shift is a change of Jupiter's current sheet current density, which would alter the amount of field line stretching and displ…