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Multispacecraft observations and modeling of the 22/23 June 2015 geomagnetic storm
Russell, C. T.; Anderson, B. J.; Nakamura, R. +9 more
The magnetic storm of 22-23 June 2015 was one of the largest in the current solar cycle. We present in situ observations from the Magnetospheric Multiscale Mission (MMS) and the Van Allen Probes (VAP) in the magnetotail, field-aligned currents from AMPERE (Active Magnetosphere and Planetary Electrodynamics Response), and ionospheric flow data from…
Ceres: Sulfur deposits and graphitized carbon
Vilas, Faith; Li, Jian-Yang; Hendrix, Amanda R.
We report new results from observations of the dwarf planet Ceres using the Hubble Space Telescope in the spectral range 1160-5700 Å. Comparisons between Ceres' UV-visible spectra and laboratory measurements indicate that both sulfur species and graphitized carbon are important on Ceres' surface. We find a latitudinal gradient in UV absorption, wi…
Electric fields associated with small-scale magnetic holes in the plasma sheet: Evidence for electron currents
Stawarz, Julia E.; Goodrich, Katherine A.; Ergun, Robert E.
We report observations of magnetic holes (MHs) in the near-Earth (8 RE to 12 RE) plasma sheet that have physical sizes perpendicular to the magnetic field (B) on the order of the ion Larmor radius (ρi) and, more importantly, have current layers less than ρi in thickness. Small-scale MHs can have >90% …
Compressible turbulence with slow-mode waves observed in the bursty bulk flow of plasma sheet
Dunlop, M.; Cao, Jinbin; Fu, Huishan +2 more
In this paper, we report the evidence of compressible turbulence with slow-mode waves in a bursty bulk flow of plasma sheet. This compressible turbulence is characterized by a multiscale (1-60 s) anticorrelation between plasma density and magnetic field strength. Besides, the magnetic compressibility spectrum stays nearly constant at all the measu…
SAPS onset timing during substorms and the westward traveling surge
Mishin, Evgeny, V.
We present multispacecraft observations in the magnetosphere and conjugate ionosphere of the onset time of subauroral polarization streams (SAPS) and tens of keV ring current injections on the duskside in three individual substorms. This is probably the first unequivocal determination of the substorm SAPS onset timing. The time lag between the SAP…
Formation of layers of methane in the atmosphere of Mars after surface release
Daerden, F.; Neary, L.; Viscardy, S.
Simulations with a general circulation model for the atmosphere of Mars show that surface emissions of methane can result in a highly nonuniform vertical distribution throughout the atmosphere, including the formation of layers, during the first weeks after the release. The fate of the released methane is determined by the global circulation patte…
Constraints on an exosphere at Ceres from Hubble Space Telescope observations
Saur, Joachim; Roth, Lorenz; Feldman, Paul D. +5 more
We report far ultraviolet observations of Ceres obtained with the Cosmic Origin Spectrograph (COS) of the Hubble Space Telescope in the search for atomic emissions from an exosphere. The derived brightnesses at the oxygen lines at 1304 Å and 1356 Å are consistent with zero signals within the 1σ propagated statistical uncertainties. The OI 1304 Å b…
Dynamics of the flares in the active polar region of Jupiter
Badman, S. V.; Bonfond, B.; Gérard, J. -C. +2 more
The duskside of the polar region of Jupiter's UV aurorae, called the active region, sometimes exhibits quasiperiodic (QP) flares on timescales of 2-3 min. Based on Hubble Space Telescope Far-UV time-tag images, we show for the first time that the Northern Hemisphere also displays QP flares. The area covered by these flares can reach up to 2.4 × 10…
Quantitative prediction of type II solar radio emission from the Sun to 1 AU
Cairns, Iver H.; Schmidt, J. M.
Coronal mass ejections (CMEs) are frequently associated with shocks and type II solar radio bursts. Despite involving fundamental plasma physics and being the archetype for collective radio emission from shocks, type II bursts have resisted detailed explanation for over 60 years. Between 29 November and 1 December 2013 the two widely separated spa…
Hybrid simulation of Titan's interaction with the supersonic solar wind during Cassini's T96 flyby
Simon, Sven; Motschmann, Uwe; Neubauer, Fritz M. +5 more
By applying a hybrid (kinetic ions and fluid electrons) simulation code, we study the plasma environment of Saturn's largest moon Titan during Cassini's T96 flyby on 1 December 2013. The T96 encounter marks the only observed event of the entire Cassini mission where Titan was located in the supersonic solar wind in front of Saturn's bow shock. Our…