scholarly journals Imaging magnetospheric boundaries at ionospheric heights

2013 ◽  
Vol 118 (11) ◽  
pp. 7294-7305 ◽  
Author(s):  
Michael Mendillo ◽  
Jeffrey Baumgardner ◽  
Joei Wroten ◽  
Carlos Martinis ◽  
Steven Smith ◽  
...  
Keyword(s):  
Magnetospheric Boundaries

Energetic electron observations of magnetospheric boundaries using the imaging electron spectrometers on Cluster and Polar

2005 ◽  
Vol 36 (10) ◽  
pp. 1916-1921
Author(s):  
J.A. Davies ◽  
M. Grande ◽  
C.H. Perry ◽  
M.W. Dunlop ◽  
M.K. Carter ◽  
...  
Keyword(s):  
Energetic Electron ◽  
Magnetospheric Boundaries

scholarly journals A statistical approach for identifying the ionospheric footprint of magnetospheric boundaries from SuperDARN observations

2008 ◽  
Vol 26 (2) ◽  
pp. 305-314 ◽  
Author(s):  
G. Lointier ◽  
T. Dudok de Wit ◽  
C. Hanuise ◽  
X. Vallières ◽  
J.-P. Villain
Keyword(s):  
Real Time ◽  
Statistical Approach ◽  
Spectral Width ◽  
Threshold Level ◽  
Strongly Correlated ◽  
Spatial Coverage ◽  
First Results ◽  
High Latitude Ionosphere ◽  
Value Decomposition ◽  
Magnetospheric Boundaries

Abstract. Identifying and tracking the projection of magnetospheric regions on the high-latitude ionosphere is of primary importance for studying the Solar Wind-Magnetosphere-Ionosphere system and for space weather applications. By its unique spatial coverage and temporal resolution, the Super Dual Auroral Radar Network (SuperDARN) provides key parameters, such as the Doppler spectral width, which allows the monitoring of the ionospheric footprint of some magnetospheric boundaries in near real-time. In this study, we present the first results of a statistical approach for monitoring these magnetospheric boundaries. The singular value decomposition is used as a data reduction tool to describe the backscattered echoes with a small set of parameters. One of these is strongly correlated with the Doppler spectral width, and can thus be used as a proxy for it. Based on this, we propose a Bayesian classifier for identifying the spectral width boundary, which is classically associated with the Polar Cap boundary. The results are in good agreement with previous studies. Two advantages of the method are: the possibility to apply it in near real-time, and its capacity to select the appropriate threshold level for the boundary detection.

scholarly journals Strong sunward propagating flow bursts in the night sector during quiet solar wind conditions: SuperDARN and satellite observations

2002 ◽  
Vol 20 (6) ◽  
pp. 771-779 ◽  
Author(s):  
C. Senior ◽  
J.-C. Cerisier ◽  
F. Rich ◽  
M. Lester ◽  
G. K. Parks
Keyword(s):  
Convective Transport ◽  
High Time Resolution ◽  
Polar Cap ◽  
Particle Precipitation ◽  
Phase Velocities ◽  
Plasma Injection ◽  
Night Side ◽  
Magnetospheric Boundaries ◽  
Auroral Particle Precipitation ◽  
Imf Clock Angle

Abstract. High-time resolution data from the two Iceland SuperDARN HF radars show very strong nightside convection activity during a prolonged period of low geomagnetic activity and northward interplanetary magnetic field (IMF). Flows bursts with velocities ranging from 0.8 to 1.7 km/s are observed to propagate in the sunward direction with phase velocities up to 1.5 km/s. These bursts occur over several hours of MLT in the 20:00–01:00 MLT sector, in the evening-side sunward convection. Data from a simultaneous DMSP pass and POLAR UVI images show a very contracted polar cap and extended regions of auroral particle precipitation from the magnetospheric boundaries. A DMSP pass over the Iceland-West field-of-view while one of these sporadic bursts of enhanced flow is observed, indicates that the flow bursts appear within the plasma sheet and at its outward edge, which excludes Kelvin-Helmholtz instabilities at the magnetopause boundary as the generation mechanism. In the nightside region, the precipitation is more spot-like and the convection organizes itself as clockwise U-shaped structures. We interpret these flow bursts as the convective transport following plasma injection events from the tail into the night-side ionosphere. We show that during this period, where the IMF clock angle is around 70°, the dayside magnetosphere is not completely closed.Key words. Ionosphere (Auroral ionosphere; Ionospheremagnetosphere interactions; Particle precipitation)

Key problems in space physics: Thin magnetospheric boundaries

2003 ◽  
Vol 51 (12) ◽  
pp. 713
Author(s):  
Charles Farrugia ◽  
Harald Kucharek
Keyword(s):  
Space Physics ◽  
Magnetospheric Boundaries

scholarly journals Survey of energetic O<Sup>+</sup> ions near the dayside mid-latitude magnetopause with Cluster

2005 ◽  
Vol 23 (4) ◽  
pp. 1281-1294 ◽  
Author(s):  
M. Bouhram ◽  
B. Klecker ◽  
G. Paschmann ◽  
S. Haaland ◽  
H. Hasegawa ◽  
...  
Keyword(s):  
Plasma Sheet ◽  
Solar Maximum ◽  
Mass Density ◽  
Mass Composition ◽  
Helmholtz Instability ◽  
Time Index ◽  
Reconnection Region ◽  
Cluster Ion ◽  
Magnetospheric Boundaries ◽  
Event Basis

Abstract. Since December 2000, the Cluster satellites have been conducting detailed measurements of the magnetospheric boundaries and have confirmed the unambiguous presence of ions of terrestrial origin (e.g. O+ in regions adjacent to the dayside, mid-latitude magnetopause. In the present paper, we focus on the statistical properties of the O+ ion component at energies ranging from 30eV up to 40keV, using three years of ion data at solar maximum from the Cluster Ion Spectrometry (CIS) experiment aboard two Cluster spacecraft. The O+ density decreases on average by a factor of 6, from 0.041 to 7x10-3cm-3 when crossing the magnetopause from the magnetosphere to the magnetosheath, but depends on several parameters, such as the geomagnetic activity or the modified disturbed storm time index (Dst*), and on their location. The O+ density is significantly higher in the dusk-side than in the dawn side region, which is consistent with the view that they originate mainly from the plasma sheet. A remarkable finding is that inward of the magnetopause, O+ is the dominant contributor to the mass density 30% of the time on the dusk-side in comparison to 3% in the dawnside and 4% near noon. On an event basis in the dusk flank of the magnetopause, we point out that O+ ions, when dominating the mass composition, lower the threshold for generating the Kelvin-Helmholtz instability, which may allow plasma exchange between the magnetosheath and the plasma sheet. We also discuss the effect of a substantial O+ ion component when present in a reconnection region.

Energetic Particles in the Inner Heliosphere: Solar Orbiter

2020 ◽  
Author(s):  
Robert F. Wimmer-Schweingruber ◽  
Javier Rodriguez-Pacheco ◽  
Stephan Böttcher ◽  
Ignacio Cernuda ◽  
Nina Dresing ◽  
...  
Keyword(s):  
Solar Flares ◽  
Activity Cycle ◽  
Solar Activity Cycle ◽  
Energetic Particles ◽  
Angle Distribution ◽  
Seed Particles ◽  
Transport Effects ◽  
Singly Charged ◽  
Magnetospheric Boundaries ◽  
Accelerated Particles

&lt;p&gt;To be measured as energetic particles in the heliosphere ions and electrons must undergo three processes: injection, acceleration, and transport. Suprathermal seed particles have speeds well above the fast magnetosonic speed in the solar wind frame of reference and can vary from location to location and within the solar activity cycle. Acceleration sites include reconnecting current sheets in solar flares or magnetospheric boundaries, shocks in the solar corona, heliosphere and a planetary obstacles, as well as planetary magnetospheres. Once accelerated, particles are transported from the acceleration site into and throughout the heliosphere. Thus, by investigating properties of energetic particles such as their composition, energy spectra, pitch-angle distribution, etc. one can attempt to distinguish their origin or injection and acceleration site. This in turn allows us to better understand transport effects whose underlying microphysics is also a key ingredient in the acceleration of particles.&lt;/p&gt;&lt;p&gt;In this presentation we will present some clear examples which link energetic particles from their observing site to their source locations. These include Jupiter electrons, singly-charged He ions from CIRs, and 3He from solar flares. We will compare these examples with the measurement capabilities of the Energetic Particle Detector (EPD) on Solar Orbiter and consider implications for the key science goal of Solar Orbiter and Solar Proble Plus &amp;#8211; How the Sun creates and controls the heliosphere.&lt;/p&gt;

scholarly journals Statistical study of ICME effects on Mercury's magnetospheric boundaries and northern cusp region from MESSENGER

2017 ◽  
Vol 122 (5) ◽  
pp. 4960-4975 ◽  
Author(s):  
Reka M. Winslow ◽  
Lydia Philpott ◽  
Carol S. Paty ◽  
Noé Lugaz ◽  
Nathan A. Schwadron ◽  
...  
Keyword(s):  
Statistical Study ◽  
Cusp Region ◽  
Magnetospheric Boundaries
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