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Energetic Hydrogen and Oxygen Atoms Observed on the Nightside of Mars
Fedorov, A.; Barabash, S.; Lundin, R. +5 more
We present measurements of energetic hydrogen and oxygen atoms (ENAs) on the nightside of Mars detected by the neutral particle detector (NPD) of ASPERA-3 on Mars Express. We focus on the observations for which the field-of-view of NPD was directed at the nightside of Mars or at the region around the limb, thus monitoring the flow of ENAs towards …
ICMEs at High Latitudes and in the Outer Heliosphere. Report of Working Group H
Lario, D.; Balogh, A.; Rodriguez, L. +14 more
Interplanetary coronal mass ejections (ICMEs) propagate into the outer heliosphere, where they can have a significant effect on the structure, evolution, and morphology of the solar wind, particularly during times of high solar activity. They are known to play an important role in cosmic ray modulation and the acceleration of energetic particles. …
IMF Direction Derived from Cycloid-Like Ion Distributions Observed by Mars Express
Coates, A. J.; Kallio, E.; Fedorov, A. +29 more
Although the Mars Express (MEX) does not carry a magnetometer, it is in principle possible to derive the interplanetary magnetic field (IMF) orientation from the three dimensional velocity distribution of pick-up ions measured by the Ion Mass Analyser (IMA) on board MEX because pick-up ions' orbits, in velocity phase space, are expected to gyrate …
Global Response of Martian Plasma Environment to an Interplanetary Structure: From Ena and Plasma Observations at Mars
Barabash, S.; Lundin, R.; Futaana, Y. +4 more
As a part of the global plasma environment study of Mars and its response to the solar wind, we have analyzed a peculiar case of the subsolar energetic neutral atom (ENA) jet observed on June 7, 2004 by the Neutral Particle Detector (NPD) on board the Mars Express satellite. The "subsolar ENA jet" is generated by the interaction between the solar …
Shocks: Commonalities in Solar-Terrestrial Chains
Schwartz, Steven J.
Shocks are found throughout the heliosphere, wherever supersonic (or super-magnetosonic) flows encounter obstacles or other, slowly moving, media. Although some of the physical parameters are in different regimes, all shocks heat and decelerate the media incident upon them. Most shocks must propagate in a collisionless plasma, thereby adding impor…
Asymmetries in Mars' Exosphere. Implications for X-ray and ENA Imaging
Holmström, Mats
Observations and simulations show that Mars' atmosphere has large seasonal variations. Total atmospheric density can have an order of magnitude latitudinal variation at exobase heights. By numerical simulations we show that these latitude variations in exobase parameters induce asymmetries in the hydrogen exosphere that propagate to large distance…
Energisation of O+ and O+ 2 Ions at Mars: An Analysis of a 3-D Quasi-Neutral Hybrid Model Simulation
Kallio, E.; Fedorov, A.; Janhunen, P. +12 more
We have studied the loss of O+ and O+2 ions at Mars with a numerical model. In our quasi-neutral hybrid model ions (H+, He++, O+, O+2) are treated as particles while electrons form a massless charge-neutralising fluid. The employed model version does not includ…
Substorms and Their Solar Wind Causes
Nakamura, Rumi
Consequences of the solar wind input observed as large scale magnetotail dynamics during substorms are reviewed, highlighting results from statistical studies as well as global magnetosphere/ionosphere observations. Among the different solar wind input parameters, the most essential one to initiate reconnection relatively close to the Earth is a s…
Observations of the Martian Subsolar ENA Jet Oscillations
Fedorov, A.; Barabash, S.; Futaana, Y. +1 more
The Neutral Particle Detector (NPD) of the ASPERA-3 experiment (Analyser of Space Plasmas and Energetic Atoms) on board the Mars Express (MEX) spacecraft observed an intense flux of H ENAs (energetic neutral atoms) with average energy of about 1.5 keV emitted anisotropically from the subsolar region of Mars. The NPD detected the ENA jet near the b…
Review of Ionospheric Effects of Solar Wind Magnetosphere Coupling in the Context of the Expanding Contracting Polar Cap Boundary Model
Wild, J. A.; Lester, M.; Milan, S. E. +1 more
This paper reviews the coupling between the solar wind, magnetosphere and ionosphere. The coupling between the solar wind and Earth’s magnetosphere is controlled by the orientation of the Interplanetary Magnetic Field (IMF). When the IMF has a southward component, the coupling is strongest and the ionospheric convection pattern that is generated i…