Search Publications
The September 2017 SEP Event in Context With the Current Solar Cycle: Mars Express ASPERA-3/IMA and MAVEN/SEP Observations
Holmström, Mats; Futaana, Yoshifumi; Ramstad, Robin +5 more
We use Mars Atmosphere and Volatile Evolution/Solar Energetic Particle (MAVEN/SEP) data to estimate the ranges of particle energies that generate background noise in the Analyzer of Space Plasmas and Energetic Atoms-3/Ion Mass Analyzer (IMA) instrument on Mars Express. The particles that generate IMA background counts are estimated to be electrons…
Ion Acceleration by Flux Transfer Events in the Terrestrial Magnetosheath
Vainio, R.; Palmroth, M.; Turc, L. +6 more
We report ion acceleration by flux transfer events in the terrestrial magnetosheath in a global two-dimensional hybrid-Vlasov polar plane simulation of Earth's solar wind interaction. In the model we find that propagating flux transfer events created in magnetic reconnection at the dayside magnetopause drive fast-mode bow waves in the magnetosheat…
Circulation of Venusian Atmosphere at 90-110 km Based on Apparent Motions of the O2 1.27 µm Nightglow From VIRTIS-M (Venus Express) Data
Piccioni, G.; Zasova, L. V.; Khatuntsev, I. V. +2 more
The paper is devoted to the investigation of Venus mesosphere circulation at 90-110 km altitudes, where tracking of the O2(a1Δg) 1.27 µm nightglow is practically the only method of studying the circulation. The images of the nightglow were obtained by VIRTIS-M on Venus Express over the course of more than 2 y…
An Empirical Model of the Variation of the Solar Lyman-α Spectral Irradiance
Kretzschmar, Matthieu; Curdt, Werner; Snow, Martin
We propose a simple model that computes the spectral profile of the solar irradiance in the hydrogen Lyman alpha line, H Ly-α (121.567 nm), from 1947 to present. Such a model is relevant for the study of many astronomical environments, from planetary atmospheres to interplanetary medium. This empirical model is based on the SOlar Heliospheric Obse…
The Oxygen Ion Circulation in The Outer Terrestrial Magnetosphere and Its Dependence on Geomagnetic Activity
Nilsson, H.; Slapak, R.
We have quantified the O+ transports in the plasma sheet and lobes (-20 < XGSM<-10RE) and their dependencies on geomagnetic activity, Kp, using Cluster data. We found that they have similar behavior as the polar region O+ outflow as well as the O+ fluxes in the plasma mantle and high-lat…
Heliospheric Conditions at Saturn During Cassini's Ring-Grazing and Proximal Orbits
Krupp, N.; Jackman, C. M.; Roussos, E. +6 more
We surveyed energetic charged particle measurements by Cassini between 2016 and the end of the mission in order to identify transients of solar energetic particles and galactic cosmic rays. Such transients offer hints about the state of the heliosphere and valuable context for interpreting space weather phenomena in Saturn's magnetosphere. The per…
Extremely Low-Frequency Waves Inside the Diamagnetic Cavity of Comet 67P/Churyumov-Gerasimenko
Gunell, H.; Eriksson, A.; Karlsson, T. +7 more
The European Space Agency/Rosetta mission to comet 67P/Churyumov-Gerasimenko has provided several hundred observations of the cometary diamagnetic cavity induced by the interaction between outgassed cometary particles, cometary ions, and the solar wind magnetic field. Here we present the first electric field measurements of four preperihelion and …
Saturn's Innermost Radiation Belt Throughout and Inward of the D-Ring
Krupp, N.; Roussos, E.; Mitchell, D. G. +6 more
Cassini discovered Saturn's innermost radiation belt during the end of its mission. The belt is populated with relativistic protons, probably up to the trapping limit of ≈20 GeV. It extends from Saturn's dense atmosphere into and throughout the D-ring. The A-C rings separate this belt entirely from the previously known radiation belts, suggesting …
Photometric Modeling and VIS-IR Albedo Maps of Dione From Cassini-VIMS
Buratti, B. J.; Clark, R. N.; Stephan, K. +6 more
We report about visible and infrared albedo maps and spectral indicators of Dione's surface derived from the complete Visual and Infrared Mapping Spectrometer (VIMS) data set acquired between 2004 and 2017 during the Cassini tour in Saturn's system. Maps are derived by applying a photometric correction necessary to disentangle the intrinsic albedo…
Energetic Neutral and Charged Particle Measurements in the Inner Saturnian Magnetosphere During the Grand Finale Orbits of Cassini 2016/2017
Krupp, N.; Dougherty, M. K.; Roussos, E. +6 more
We give an overview of the charged and neutral particle measurements during the Grand Finale of Cassini performed by the Magnetosphere Imaging Instrument, MIMI, on board. The first in situ measurements of MeV particles between the D-ring and the atmosphere of the planet showed protons with energies above 300 MeV with higher count rates when magnet…