Search Publications
Seasonal Changes in Hydrogen Escape From Mars Through Analysis of HST Observations of the Martian Exosphere Near Perihelion
Villanueva, G. L.; Bertaux, J. L.; Clarke, J. T. +5 more
Hubble Space Telescope (HST) observations of the Martian hydrogen exosphere in Lyman α are presented in this paper for a period when Mars passed perihelion and southern summer solstice in its orbit. The peak intensity in the exospheric Lyman α brightness was recorded after Mars went past its perihelion, slightly after southern summer solstice. The…
Ion-Scale Wave Properties and Enhanced Ion Heating Across the Low-Latitude Boundary Layer During Kelvin-Helmholtz Instability
Nykyri, K.; Moore, T. W.; Dimmock, A. P.
In the Earth's magnetosphere, the magnetotail plasma sheet ions are much hotter than in the shocked solar wind. On the dawn sector, the cold-component ions are more abundant and hotter by 30-40% when compared to the dusk sector. Recent statistical studies of the flank magnetopause and magnetosheath have shown that the level of temperature asymmetr…
Comparing and contrasting dispersionless injections at geosynchronous orbit during a substorm event
Daly, P. W.; Khotyaintsev, Y.; Kozak, L. +3 more
Particle injections in the magnetosphere transport electrons and ions from the magnetotail to the radiation belts. Here we consider generation mechanisms of "dispersionless" injections, namely, those with simultaneous increase of the particle flux over a wide energy range. In this study we take advantage of multisatellite observations which simult…
North-south asymmetries in cold plasma density in the magnetotail lobes: Cluster observations
Snekvik, K.; Østgaard, N.; Tenfjord, P. +7 more
In this paper, we present observations of cold (0-70 eV) plasma density in the magnetotail lobes. The observations and results are based on 16 years of Cluster observation of spacecraft potential measurements converted into local plasma densities. Measurements from all four Cluster spacecraft have been used, and the survey indicates a persistent a…
A multispacecraft event study of Pc5 ultralow-frequency waves in the magnetosphere and their external drivers
Wang, Chih-Ping; Liu, Terry Z.; Angelopoulos, Vassilis +9 more
We investigate a quiet time event of magnetospheric Pc5 ultralow-frequency (ULF) waves and their likely external drivers using multiple spacecraft observations. Enhancements of electric and magnetic field perturbations in two narrow frequency bands, 1.5-2 mHz and 3.5-4 mHz, were observed over a large radial distance range from r 5 to 11 RE
A new solar wind-driven global dynamic plasmapause model: 1. Database and statistics
Liemohn, Michael W.; Gallagher, Dennis L.; He, Fei +5 more
A large database, possibly the largest plasmapause location database, with 49,119 plasmapause crossing events from the in situ observations and 3957 plasmapause profiles (corresponding to 48,899 plasmapause locations in 1 h magnetic local time (MLT) intervals) from optical remote sensing from 1977 to 2015 by 18 satellites is compiled. The response…
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…