Search Publications
Influence of interplanetary coronal mass ejections on the peak intensity of solar energetic particle events
Lario, D.; Karelitz, A.
We study whether the presence of coronal mass ejections (CMEs) in interplanetary space (ICMEs) affects the maximum intensity of solar energetic particle (SEP) events. We compute the maximum intensity of 175-315 keV electron and 9-15, 15-40, and 40-80 MeV proton fluxes measured during the prompt component of 147 western SEP events observed near Ear…
First direct observation of sputtered lunar oxygen
Barabash, S.; Holmström, M.; Futaana, Y. +5 more
We present the first direct measurement of neutral oxygen in the lunar exosphere, detected by the Chandrayaan-1 Energetic Neutral Analyzer (CENA). With the lunar surface consisting of about 60% of oxygen in number, the neutral oxygen detected in CENA's energy range (11 eV-3.3 keV) is attributed to have originated from the lunar surface, where it w…
Multispacecraft Cluster observations of quasiperiodic emissions close to the geomagnetic equator
Pickett, J. S.; Santolík, O.; Němec, F.
We present a detailed analysis of three electromagnetic wave events observed by the Cluster Wide-Band Data instruments at frequencies of a few kilohertz, which exhibit a periodic time modulation of the wave intensity (quasiperiodic emissions). The events were measured when crossing the geomagnetic equator at radial distances of about 3-4 RE
Anomalous dynamics of the extremely compressed magnetosphere during 21 January 2005 magnetic storm
Veselovsky, I. S.; Myagkova, I. N.; Dmitriev, A. V. +7 more
The dayside magnetosphere and proton radiation belt were analyzed during unusual magnetic storm on 21 January 2005. We have found that from 1712 to 2400 UT, the subsolar magnetopause was continuously located inside geosynchronous orbit due to strong compression. The compression was extremely strong from 1846 to 2035 UT when the dense plasma of fas…
Cassini multi-instrument assessment of Saturn's polar cap boundary
Gurnett, D. A.; Krupp, N.; Dougherty, M. K. +10 more
We present the first systematic investigation of the polar cap boundary in Saturn's high-latitude magnetosphere through a multi-instrument assessment of various Cassini in situ data sets gathered between 2006 and 2009. We identify 48 polar cap crossings where the polar cap boundary can be clearly observed in the step in upper cutoff of auroral his…
On the fine structure of dipolarization fronts
Dandouras, I.; Walker, S. N.; Runov, A. +4 more
Measurements from the closely spaced Cluster spacecraft are used to study the structure of the magnetic and electric fields within the magnetic ramp of dipolarization fronts (DF) observed close to the neutral sheet and the midnight meridian (YGSM<3RE). The spacecraft separation was small enough (<300 km) to treat the ma…
Testing linear theory of EMIC waves in the inner magnetosphere: Cluster observations
Sauvaud, J. -A.; Klecker, B.; Kistler, L. M. +8 more
In this paper, we test whether time periods with hot proton temperature anisotropy are associated with electromagnetic ion cyclotron (EMIC) waves and whether the plasma conditions during the observed waves satisfy the linear theory threshold condition. We identify 865 events observed by the Composition Distribution Function instrument onboard Clus…
Plasma and energetic particle behaviors during asymmetric magnetic reconnection at the magnetopause
Glassmeier, K. -H.; Zhang, H.; Zong, Q. -G. +6 more
The factors controlling asymmetric reconnection and the role of the cold plasma population in the reconnection process are two outstanding questions. We present a case study of multipoint Cluster observations demonstrating that the separatrix and flow boundary angles are greater on the magnetosheath than on the magnetospheric side of the magnetopa…
Hydrocarbon ions in the lower ionosphere of Saturn
Moses, J. I.; Black, J. H.; Kim, Y. H. +1 more
Radio occultation measurements of the Saturn ionosphere have shown that persistent but variable electron density layers appear well below the major peaks. We model here the region of hydrocarbon ions that is below the main peak and is produced by absorption of solar photons in the wavelength range 842 to 1116 Å, which penetrate to altitudes below …
Transmission of large-amplitude ULF waves through a quasi-parallel shock at Venus
Zhang, Tielong; Wang, Shui; Huang, Can +4 more
There exist large-amplitude ultralow frequency (ULF) waves in the upstream region of a quasi-parallel shock, which are excited due to the reflected ions by the shock. These waves are then brought back to the shock by the solar wind, and at last they coalesce and merge with the shock. In this paper, with the magnetic field measurements from Venus E…