Search Publications
Isolated High-Density Structures in Magnetic Anomaly Regions of the Martian Lower Ionosphere
Venkateswara Rao, N.; Leelavathi, V.; Mohanamanasa, P. +1 more
The occurrence of density structures in magnetic anomaly regions is one of the prominent features of the Martian ionosphere. These structures, in general, occur at altitudes above the main peak. In the present study, we analyze four cases of unusually strong oblique echoes that occur in magnetic anomaly regions and are observed by the Mars Express…
Oxygen Ion Butterfly Distributions Observed in a Magnetotail Dipolarizing Flux Bundle
Zhang, H.; Sun, W. J.; Fu, S. Y. +8 more
Cluster observed two intermittent oxygen ion (O+) flux enhancements with energy dispersions in a dipolarizing flux bundle, which is known as a region of enhanced northward magnetic field (Bz) embedded in the earthward high-speed flow. The flux enhancements of O+ show clear pitch angle dependences, which are termed …
Effect of Dust Storm and GCR Impact on the Production Rate of O3+ in MY 28 and MY 29: Modeling and SPICAM Observation
Haider, S. A.; Masoom, J.; Bougher, S. +1 more
We have developed a seasonally dependent energy loss model to calculate the zonally averaged production rates of O3+ due to impact of galactic cosmic rays in the dayside troposphere of Mars between solar longitudes (Ls) 0° and 360° at low latitudes (2°N, 2°S, 25°N, and 25°S), midlatitudes (45°N and 45°S), and high …
Finding the Normal Direction of Interplanetary Directional Discontinuities—A New Scheme
Wu, D. J.; Yang, L.; Yang, Y. -H. +2 more
Directional discontinuities (DDs) are common structures in the interplanetary space. Correctly determining the normal of a DD is important to understand the changes of phase fronts of magnetic fields adjacent to a discontinuity as well as helpful for the applications in many regimes of space physics research. In this work, we propose a new scheme …
Theoretical Prediction of Asymmetric Instability of Drift Kinetic Alfven Waves in Anisotropic Plasmas
Ilie, Raluca; Chen, Lunjin; Bashir, M. F.
The asymmetric instability of drift kinetic Alfvén waves (DKAWs) is analyzed to study the interplay between the density inhomogeneity and the temperature anisotropy, including the wave-particle interaction and finite ion Larmor radius effects. The asymmetric behavior arises due to the opposite diamagnetic drifts of electrons and ions and quantifie…
Oscillatory Flows in the Magnetotail Plasma Sheet: Cluster Observations of the Distribution Function
Gunell, H.; Nilsson, H.; Hamrin, M. +7 more
Plasma dynamics in Earth's magnetotail is often studied using moments of the distribution function, which results in losing information on the kinetic properties of the plasma. To better understand oscillatory flows observed in the midtail plasma sheet, we investigate two events, one in each hemisphere, in the transition region between the central…
Investigation of a Confined C-Class Flare in an Arch Filament System Close to a Regular Sunspot
Louis, Rohan Eugene
A moderate C1.1 class confined flare is investigated here, which occurred on 24 September 2013 at 22:56 UT, in an arch filament system close to a regular, unipolar sunspot. Spectropolarimetric observations from the Tenerife Infrared Polarimeter at the 70-cm German Vacuum Tower Telescope were combined with data from the Helioseismic Magnetic Imager…
Energetic Electron Patterns in the New SLS5 Longitude System
Mitchell, D. G.; Carbary, J. F.; Ye, Shengyi
Energetic electron (110-300 keV) fluxes collected during the entire 13-year Cassini mission are organized in the new Saturn longitude system (SLS5). This system is based on Saturn radio emissions, varies slowly in time and has a north and a south branch. When the fluxes are organized in SLS5 longitudes and magnetodisk coordinates, they display an …
Vertical Current Density Structure of Saturn's Equatorial Current Sheet
Ray, L. C.; Case, N. A.; Arridge, C. S. +1 more
Routine spacecraft encounters with the Saturn current sheet due to the passage of aperiodic waves provide the opportunity to analyze the current sheet structure. The current density is expected to peak where the field strength reaches a minimum if approximated as a Harris current sheet. However, in Earth's magnetotail this is not always the case a…
Oxygen Ion Flow Reversals in Earth's Magnetotail: A Cluster Statistical Study
Gunell, H.; Nilsson, H.; Hamrin, M. +5 more
We present a statistical study of magnetotail flows that change direction from earthward to tailward using Cluster spacecraft. More precisely, we study 318 events of particle flux enhancements in the O+ data for which the pitch angle continuously changes with time, either from 0° to 180° or from 180° to 0°. These structures are called "…