Search Publications
Radio Occultation Observations of the Solar Corona Over 1.60-1.86 R⊙: Faraday Rotation and Frequency Shift Analysis
Lionello, Roberto; Hollweg, Joseph V.; Jensen, Elizabeth A. +5 more
The study of coronal energy transport, central to the solar wind acceleration problem, relies upon accurate representation of magnetic fields and plasma electron densities. This information is difficult to obtain in middle-to-lower coronal regions that may contain complex magnetic structures. Faraday rotation (FR) solar radio occultation observati…
Variability of Intra-D Ring Azimuthal Magnetic Field Profiles Observed on Cassini's Proximal Periapsis Passes
Dougherty, M. K.; Cowley, S. W. H.; Bunce, E. J. +4 more
We overview the properties of the azimuthal magnetic fields observed during the periapsis passes of the final 23 orbits of the Cassini spacecraft, including the partial orbit at end of mission, on near equatorial field lines passing inside of Saturn's D ring. The signatures are variable in form and amplitude, though generally approximately symmetr…
Signatures of Cold Ions in a Kinetic Simulation of the Reconnecting Magnetopause
Lavraud, B.; Toledo-Redondo, S.; Aunai, N. +2 more
At the Earth's magnetopause, a low-energy ion population of ionospheric origin is commonly observed at the magnetospheric side. In this work we use a 2-D fully kinetic simulation to identify several original signatures related to the dynamics of cold ions involved in magnetic reconnection at the asymmetric dayside magnetopause. We identify several…
Beyond the Minisolar Maximum of Solar Cycle 24: Declining Solar Magnetic Fields and the Response of the Terrestrial Magnetosphere
Janardhan, P.; Ingale, M.; Bisoi, S. K.
The present study examines the response of the terrestrial magnetosphere to the long-term steady declining trends observed in solar magnetic fields and solar wind microturbulence levels since mid-1990s that has been continuing beyond the minisolar maximum of cycle 24. A detailed analysis of the response of the terrestrial magnetosphere has been ca…
Recent Advancements and Remaining Challenges Associated With Inner Magnetosphere Cross-Energy/Population Interactions (IMCEPI)
Jordanova, Vania K.; Yu, Yiqun; Liemohn, Mike W. +2 more
The geospace inner magnetosphere, within about 10 Earth radii, contains various plasma populations with energy from a few electron volts to megaelectron volts and plays important roles in regulating the energy density of the magnetosphere, the magnetic field configuration, and wave dynamics. As an integrated part of the magnetosphere, the inner ma…
Proton Temperature Anisotropies in the Plasma Environment of Venus
Futaana, Y.; Zhang, T. L.; Nilsson, H. +5 more
Velocity distribution functions (VDFs) are a key to understanding the interplay between particles and waves in a plasma. Any deviation from an isotropic Maxwellian distribution may be unstable and result in wave generation. Using data from the ion mass spectrometer IMA (Ion Mass Analyzer) and the magnetometer (MAG) onboard Venus Express, we study …
Cassini Radio Occultation Observations of Titan's Ionosphere: The Complete Set of Electron Density Profiles
Dalba, Paul A.; Withers, Paul
Titan's ionosphere is an important component of the moon's environment. Ionospheric densities above ≈900 km have been studied with in situ measurements, but few density profiles for lower altitudes has been reported. Here we report the generation of the complete set of twenty ionospheric electron density profiles from the Cassini Radio Science Sub…
Observations of Continuous Quasiperiodic Auroral Pulsations on Saturn in High Time-Resolution UV Auroral Imagery
Badman, S. V.; Yao, Z. H.; Bader, A. +2 more
Saturn's aurora represents the ionospheric response to plasma processes occurring in the planet's entire magnetosphere. Short-lived ∼1-hr quasiperiodic high-energy electron injections, frequently observed in in situ particle and radio measurements, should therefore entail an associated flashing auroral signature. This study uses high time-resoluti…
Can Reconnection be Triggered as a Solar Wind Directional Discontinuity Crosses the Bow Shock? A Case of Asymmetric Reconnection
Gunell, H.; Hamrin, M.; Vaivads, A. +7 more
Here we present some unique observations of reconnection at a quasi-perpendicular bow shock as an interplanetary directional discontinuity (DD) is crossing it simultaneously with the Magnetospheric Multiscale (MMS) mission. There are no burst data, but available data show indications of ongoing reconnection at the shock southward of MMS: a bifurca…
Observations of Asymmetric Lobe Convection for Weak and Strong Tail Activity
Østgaard, N.; Tenfjord, P.; Reistad, J. P. +6 more
In this study we use high-quality convection data from the Electron Drift Instrument on board Cluster to investigate how near-Earth tail activity affects the average convection pattern in the magnetotail lobes when the interplanetary magnetic field has a dominating east-west (By) component. Two different proxies have been used to repres…