Search Publications
Using the Coronal Evolution to Successfully Forward Model CMEs' In Situ Magnetic Profiles
Gopalswamy, N.; Kay, C.
Predicting the effects of a coronal mass ejection (CME) impact requires knowing if impact will occur, which part of the CME impacts, and its magnetic properties. We explore the relation between CME deflections and rotations, which change the position and orientation of a CME, and the resulting magnetic profiles at 1 AU. For 45 STEREO-era, Earth-im…
Nitric oxide nightglow and Martian mesospheric circulation from MAVEN/IUVS observations and LMD-MGCM predictions
Forget, F.; Montmessin, F.; González-Galindo, F. +19 more
We report results from a study of nitric oxide nightglow over the northern hemisphere of Mars during winter, the southern hemisphere during fall equinox, and equatorial latitudes during summer in the northern hemisphere based on observations of the δ and γ bands between 190 and 270 nm by the Imaging UltraViolet Spectrograph (IUVS) on the Mars Atmo…
Detection of meteoroid hypervelocity impacts on the Cluster spacecraft: First results
Mann, Ingrid; Vaverka, Jakub; Pellinen-Wannberg, Asta +5 more
We present the first study of dust impact events on one of the Earth-orbiting Cluster satellites. The events were identified in the measurements of the wide band data (WBD) instrument on board the satellite operating in monopole configuration. Since 2009 the instrument is operating in this configuration due to the loss of three electric probes and…
Occurrence frequency and location of magnetic islands at the dayside magnetopause
Allen, R. C.; Fuselier, S. A.; Trattner, K. J. +2 more
Simulations of magnetic reconnection often predict the formation of magnetic islands forming and propagating out through the reconnection exhaust region. However, to date, only a few observations of magnetic islands at the Earth's magnetopause have been identified and analyzed. Crossings near reconnection sites at the dayside magnetopause by Clust…
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 …