The Experts below are selected from a list of 105 Experts worldwide ranked by ideXlab platform
E A Kronberg - One of the best experts on this subject based on the ideXlab platform.
-
Correction to “Oxygen and hydrogen ion abundance in the near‐Earth Magnetosphere: Statistical results on the response to the geomagnetic and solar wind activity conditions”
Journal of Geophysical Research, 2020Co-Authors: E A Kronberg, S Haaland, Patrick W Daly, E E Grigorenko, L M Kistler, M Franz, I DandourasAbstract:[1] The composition of ions plays a crucial role for the fundamental plasma properties in the terrestrial Magnetosphere. We investigate the oxygen-to-hydrogen ratio in the near-Earth Magnetosphere from −10 RE 274 keV O+ ion intensities, relative to the corresponding hydrogen intensities; (3) In contrast to ∼10 keV ions, the >274 keV O+ions show the strongest acceleration during growth phase and not during the expansion phase itself. This suggests a connection between the energy input to the Magnetosphere and the effective energization of energetic ions during growth phase; (4) The ratio between quiet and disturbed times for the intensities of ion ionospheric outflow is similar to those observed in the near-Earth Magnetosphere at >274 keV. Therefore, the increase of the energetic ion intensity during disturbed time is likely due to the intensification and the effective acceleration of the ionospheric source. In conclusion, the energization process in the near-Earth Magnetosphere is mass dependent and it is more effective for the heavier ions.
-
imf dependence of energetic oxygen and hydrogen ion distributions in the near Earth Magnetosphere
Journal of Geophysical Research, 2017Co-Authors: E A Kronberg, Patrick W Daly, K Nykyri, K J Trattner, Gengxiong Chen, Aimin Du, Y S GeAbstract:Energetic ion distributions in the near-Earth plasma sheet can provide important information for understanding the entry of ions into the Magnetosphere and their transportation, acceleration, and losses in the near-Earth region. In this study, 11 years of energetic proton and oxygen observations (> similar to 274 keV) from Cluster/Research with Adaptive Particle Imaging Detectors were used to statistically study the energetic ion distributions in the near-Earth region. The dawn-dusk asymmetries of the distributions in three different regions (dayside Magnetosphere, near-Earth nightside plasma sheet, and tail plasma sheet) are examined in Northern and Southern Hemispheres. The results show that the energetic ion distributions are influenced by the dawn-dusk interplanetary magnetic field (IMF) direction. The enhancement of ion intensity largely correlates with the location of the magnetic reconnection at the magnetopause. The results imply that substorm-related acceleration processes in the magnetotail are not the only source of energetic ions in the dayside and the near-Earth Magnetosphere. Energetic ions delivered through reconnection at the magnetopause significantly affect the energetic ion population in the Magnetosphere. We also believe that the influence of the dawn-dusk IMF direction should not be neglected in models of the particle population in the Magnetosphere.
-
correction to oxygen and hydrogen ion abundance in the near Earth Magnetosphere statistical results on the response to the geomagnetic and solar wind activity conditions
Journal of Geophysical Research, 2014Co-Authors: E A Kronberg, S Haaland, Patrick W Daly, E E Grigorenko, L M Kistler, M Franz, I DandourasAbstract:[1] The composition of ions plays a crucial role for the fundamental plasma properties in the terrestrial Magnetosphere. We investigate the oxygen-to-hydrogen ratio in the near-Earth Magnetosphere from −10 RE 274 keV O+ ion intensities, relative to the corresponding hydrogen intensities; (3) In contrast to ∼10 keV ions, the >274 keV O+ions show the strongest acceleration during growth phase and not during the expansion phase itself. This suggests a connection between the energy input to the Magnetosphere and the effective energization of energetic ions during growth phase; (4) The ratio between quiet and disturbed times for the intensities of ion ionospheric outflow is similar to those observed in the near-Earth Magnetosphere at >274 keV. Therefore, the increase of the energetic ion intensity during disturbed time is likely due to the intensification and the effective acceleration of the ionospheric source. In conclusion, the energization process in the near-Earth Magnetosphere is mass dependent and it is more effective for the heavier ions.
-
oxygen and hydrogen ion abundance in the near Earth Magnetosphere statistical results on the response to the geomagnetic and solar wind activity conditions oxygen abundance in the Magnetosphere
Journal of Geophysical Research, 2012Co-Authors: E A Kronberg, S Haaland, Patrick W Daly, E E Grigorenko, L M Kistler, M Franz, I DandourasAbstract:The composition of ions plays a crucial role for the fundamental plasma properties in the terrestrial Magnetosphere. We investigate the oxygen-to-hydrogen ratio in the near-Earth Magnetosphere from -10 RE 274 keV O+ ion intensities, relative to the corresponding hydrogen intensities; (3) In contrast to ~10 keV ions, the >274 keV O+ ions show the strongest acceleration during growth phase and not during the expansion phase itself. This suggests a connection between the energy input to the Magnetosphere and the effective energization of energetic ions during growth phase; (4) The ratio between quiet and disturbed times for the intensities of ion ionospheric outflow is similar to those observed in the near-Earth Magnetosphere at >274 keV. Therefore, the increase of the energetic ion intensity during disturbed time is more likely due to the intensification than to the more effective acceleration of the ionospheric source. In conclusion, the energization process in the near-Earth Magnetosphere is mass dependent and it is more effective for the heavier ions.
I Dandouras - One of the best experts on this subject based on the ideXlab platform.
-
Correction to “Oxygen and hydrogen ion abundance in the near‐Earth Magnetosphere: Statistical results on the response to the geomagnetic and solar wind activity conditions”
Journal of Geophysical Research, 2020Co-Authors: E A Kronberg, S Haaland, Patrick W Daly, E E Grigorenko, L M Kistler, M Franz, I DandourasAbstract:[1] The composition of ions plays a crucial role for the fundamental plasma properties in the terrestrial Magnetosphere. We investigate the oxygen-to-hydrogen ratio in the near-Earth Magnetosphere from −10 RE 274 keV O+ ion intensities, relative to the corresponding hydrogen intensities; (3) In contrast to ∼10 keV ions, the >274 keV O+ions show the strongest acceleration during growth phase and not during the expansion phase itself. This suggests a connection between the energy input to the Magnetosphere and the effective energization of energetic ions during growth phase; (4) The ratio between quiet and disturbed times for the intensities of ion ionospheric outflow is similar to those observed in the near-Earth Magnetosphere at >274 keV. Therefore, the increase of the energetic ion intensity during disturbed time is likely due to the intensification and the effective acceleration of the ionospheric source. In conclusion, the energization process in the near-Earth Magnetosphere is mass dependent and it is more effective for the heavier ions.
-
correction to oxygen and hydrogen ion abundance in the near Earth Magnetosphere statistical results on the response to the geomagnetic and solar wind activity conditions
Journal of Geophysical Research, 2014Co-Authors: E A Kronberg, S Haaland, Patrick W Daly, E E Grigorenko, L M Kistler, M Franz, I DandourasAbstract:[1] The composition of ions plays a crucial role for the fundamental plasma properties in the terrestrial Magnetosphere. We investigate the oxygen-to-hydrogen ratio in the near-Earth Magnetosphere from −10 RE 274 keV O+ ion intensities, relative to the corresponding hydrogen intensities; (3) In contrast to ∼10 keV ions, the >274 keV O+ions show the strongest acceleration during growth phase and not during the expansion phase itself. This suggests a connection between the energy input to the Magnetosphere and the effective energization of energetic ions during growth phase; (4) The ratio between quiet and disturbed times for the intensities of ion ionospheric outflow is similar to those observed in the near-Earth Magnetosphere at >274 keV. Therefore, the increase of the energetic ion intensity during disturbed time is likely due to the intensification and the effective acceleration of the ionospheric source. In conclusion, the energization process in the near-Earth Magnetosphere is mass dependent and it is more effective for the heavier ions.
-
oxygen and hydrogen ion abundance in the near Earth Magnetosphere statistical results on the response to the geomagnetic and solar wind activity conditions oxygen abundance in the Magnetosphere
Journal of Geophysical Research, 2012Co-Authors: E A Kronberg, S Haaland, Patrick W Daly, E E Grigorenko, L M Kistler, M Franz, I DandourasAbstract:The composition of ions plays a crucial role for the fundamental plasma properties in the terrestrial Magnetosphere. We investigate the oxygen-to-hydrogen ratio in the near-Earth Magnetosphere from -10 RE 274 keV O+ ion intensities, relative to the corresponding hydrogen intensities; (3) In contrast to ~10 keV ions, the >274 keV O+ ions show the strongest acceleration during growth phase and not during the expansion phase itself. This suggests a connection between the energy input to the Magnetosphere and the effective energization of energetic ions during growth phase; (4) The ratio between quiet and disturbed times for the intensities of ion ionospheric outflow is similar to those observed in the near-Earth Magnetosphere at >274 keV. Therefore, the increase of the energetic ion intensity during disturbed time is more likely due to the intensification than to the more effective acceleration of the ionospheric source. In conclusion, the energization process in the near-Earth Magnetosphere is mass dependent and it is more effective for the heavier ions.
Patrick W Daly - One of the best experts on this subject based on the ideXlab platform.
-
Correction to “Oxygen and hydrogen ion abundance in the near‐Earth Magnetosphere: Statistical results on the response to the geomagnetic and solar wind activity conditions”
Journal of Geophysical Research, 2020Co-Authors: E A Kronberg, S Haaland, Patrick W Daly, E E Grigorenko, L M Kistler, M Franz, I DandourasAbstract:[1] The composition of ions plays a crucial role for the fundamental plasma properties in the terrestrial Magnetosphere. We investigate the oxygen-to-hydrogen ratio in the near-Earth Magnetosphere from −10 RE 274 keV O+ ion intensities, relative to the corresponding hydrogen intensities; (3) In contrast to ∼10 keV ions, the >274 keV O+ions show the strongest acceleration during growth phase and not during the expansion phase itself. This suggests a connection between the energy input to the Magnetosphere and the effective energization of energetic ions during growth phase; (4) The ratio between quiet and disturbed times for the intensities of ion ionospheric outflow is similar to those observed in the near-Earth Magnetosphere at >274 keV. Therefore, the increase of the energetic ion intensity during disturbed time is likely due to the intensification and the effective acceleration of the ionospheric source. In conclusion, the energization process in the near-Earth Magnetosphere is mass dependent and it is more effective for the heavier ions.
-
imf dependence of energetic oxygen and hydrogen ion distributions in the near Earth Magnetosphere
Journal of Geophysical Research, 2017Co-Authors: E A Kronberg, Patrick W Daly, K Nykyri, K J Trattner, Gengxiong Chen, Aimin Du, Y S GeAbstract:Energetic ion distributions in the near-Earth plasma sheet can provide important information for understanding the entry of ions into the Magnetosphere and their transportation, acceleration, and losses in the near-Earth region. In this study, 11 years of energetic proton and oxygen observations (> similar to 274 keV) from Cluster/Research with Adaptive Particle Imaging Detectors were used to statistically study the energetic ion distributions in the near-Earth region. The dawn-dusk asymmetries of the distributions in three different regions (dayside Magnetosphere, near-Earth nightside plasma sheet, and tail plasma sheet) are examined in Northern and Southern Hemispheres. The results show that the energetic ion distributions are influenced by the dawn-dusk interplanetary magnetic field (IMF) direction. The enhancement of ion intensity largely correlates with the location of the magnetic reconnection at the magnetopause. The results imply that substorm-related acceleration processes in the magnetotail are not the only source of energetic ions in the dayside and the near-Earth Magnetosphere. Energetic ions delivered through reconnection at the magnetopause significantly affect the energetic ion population in the Magnetosphere. We also believe that the influence of the dawn-dusk IMF direction should not be neglected in models of the particle population in the Magnetosphere.
-
correction to oxygen and hydrogen ion abundance in the near Earth Magnetosphere statistical results on the response to the geomagnetic and solar wind activity conditions
Journal of Geophysical Research, 2014Co-Authors: E A Kronberg, S Haaland, Patrick W Daly, E E Grigorenko, L M Kistler, M Franz, I DandourasAbstract:[1] The composition of ions plays a crucial role for the fundamental plasma properties in the terrestrial Magnetosphere. We investigate the oxygen-to-hydrogen ratio in the near-Earth Magnetosphere from −10 RE 274 keV O+ ion intensities, relative to the corresponding hydrogen intensities; (3) In contrast to ∼10 keV ions, the >274 keV O+ions show the strongest acceleration during growth phase and not during the expansion phase itself. This suggests a connection between the energy input to the Magnetosphere and the effective energization of energetic ions during growth phase; (4) The ratio between quiet and disturbed times for the intensities of ion ionospheric outflow is similar to those observed in the near-Earth Magnetosphere at >274 keV. Therefore, the increase of the energetic ion intensity during disturbed time is likely due to the intensification and the effective acceleration of the ionospheric source. In conclusion, the energization process in the near-Earth Magnetosphere is mass dependent and it is more effective for the heavier ions.
-
oxygen and hydrogen ion abundance in the near Earth Magnetosphere statistical results on the response to the geomagnetic and solar wind activity conditions oxygen abundance in the Magnetosphere
Journal of Geophysical Research, 2012Co-Authors: E A Kronberg, S Haaland, Patrick W Daly, E E Grigorenko, L M Kistler, M Franz, I DandourasAbstract:The composition of ions plays a crucial role for the fundamental plasma properties in the terrestrial Magnetosphere. We investigate the oxygen-to-hydrogen ratio in the near-Earth Magnetosphere from -10 RE 274 keV O+ ion intensities, relative to the corresponding hydrogen intensities; (3) In contrast to ~10 keV ions, the >274 keV O+ ions show the strongest acceleration during growth phase and not during the expansion phase itself. This suggests a connection between the energy input to the Magnetosphere and the effective energization of energetic ions during growth phase; (4) The ratio between quiet and disturbed times for the intensities of ion ionospheric outflow is similar to those observed in the near-Earth Magnetosphere at >274 keV. Therefore, the increase of the energetic ion intensity during disturbed time is more likely due to the intensification than to the more effective acceleration of the ionospheric source. In conclusion, the energization process in the near-Earth Magnetosphere is mass dependent and it is more effective for the heavier ions.
L M Zelenyi - One of the best experts on this subject based on the ideXlab platform.
-
kinetic models of magnetic flux ropes observed in the Earth Magnetosphere
Physics of Plasmas, 2016Co-Authors: A A Vinogradov, I Y Vasko, A V Artemyev, E V Yushkov, A A Petrukovich, L M ZelenyiAbstract:Magnetic flux ropes (MFR) are universal magnetoplasma structures (similar to cylindrical screw pinches) formed in reconnecting current sheets. In particular, MFR with scales from about the ion inertial length to MHD range are widely observed in the Earth Magnetosphere. Typical MFR have force-free configuration with the axial magnetic field peaking on the MFR axis, whereas bifurcated MFR with an off-axis peak of the axial magnetic field are observed as well. In the present paper, we develop kinetic models of force-free and bifurcated MFR and determine consistent ion and electron distribution functions. The magnetic field configuration of the force-free MFR represents well-known Gold-Hoyle MFR (uniformly twisted MFR). We show that bifurcated MFR are characterized by the presence of cold and hot current-carrying electrons. The developed models are capable to describe MFR observed in the Earth magnetotail as well as MFR recently observed by Magnetospheric Multiscale Mission at the Earth magnetopause.
-
Non-adiabatic Ion Acceleration in the Earth Magnetotail and Its Various Manifestations in the Plasma Sheet Boundary Layer
Space Science Reviews, 2011Co-Authors: E. E. Grigorenko, L M Zelenyi, M. S. Dolgonosov, A. V. Artemiev, C. J. Owen, J.-a. Sauvaud, M. Hoshino, M. HiraiAbstract:Many physical phenomena in space involve energy dissipation which generally leads to charged particle acceleration, often up to very high energies. In the Earth Magnetosphere energy accumulation and release occur in the magnetotail, namely in its Current Sheet (CS). The kinetic analysis of non-adiabatic ion trajectories in the CS region with finite but positive normal component of the magnetic field demonstrated that this region is essentially non-uniform in terms of scattering characteristics of ion orbits and contains spatially localized, well-separated sites of enhanced and reduced chaotization. The latter represent sources from which accelerated and energy-collimated ions are ejected into Plasma Sheet Boundary Layer (PSBL) and stream towards the Earth. Numerical simulations performed as part of a Large-Scale Kinetic Model have shown the multiplet ion structure of the PSBL is formed by a set of ion beams (beamlets) localized both in physical and velocity space. This structure of the PSBL is quite different from the one produced by CS acceleration near a magnetic reconnection region in which more energetic ion beams are generated with a broad range of parallel velocities. Multi-point Cluster observations in the magnetotail PSBL not only showed that non-adiabatic ion acceleration occurs on closed magnetic field lines with at least two CS sources operating simultaneously, but also allowed an estimation of their spatial and temporal characteristics. In this paper we discuss and compare the PSBL manifestations of both mechanisms of CS particle acceleration: one based on the peculiar properties of non-adiabatic ion trajectories which operates on closed magnetic field lines and the other representing the well-explored mechanism of particle acceleration during the course of magnetic reconnection. We show that these two mechanisms supplement each other and the first operates mostly during quiescent magnetotail periods.
Lev Zelenyi - One of the best experts on this subject based on the ideXlab platform.
-
Current Sheets in the Earth Magnetotail: Plasma and Magnetic Field Structure with Cluster Project Observations
Space Science Reviews, 2015Co-Authors: Anatoli Petrukovich, Anton Artemyev, Ivan Vasko, Rumi Nakamura, Lev ZelenyiAbstract:Thin current sheets having kinetic scales are an important plasma structure, where the magnetic energy dissipation and charged particle acceleration are the most effective. It is believed that such current sheets are self-consistently formed by the specific nonadiabatic dynamics of charged particles and play a critical role in many space plasma and astrophysical objects. Current sheets in the near-Earth plasma environment, e.g., the magnetotail current sheet, are readily available for in-situ investigations. The dedicated multi-spacecraft Cluster mission have revealed basic properties of this current sheet, which are presented in this review: typical spatial profiles of magnetic field and current density, distributions of plasma temperature and density, role of heavy ions and electron currents, etc. Being important for the Earth Magnetosphere physics, the new knowledge also could provide the basis for advancement in general plasma physics as well as in plasma astrophysics.
