scholarly journals Observation of magnetic reconnection and current sheets in the solar wind

2009 ◽  
Vol 5 (S264) ◽  
pp. 369-372
Author(s):  
Pablo R. Muñoz ◽  
Abraham C.-L. Chian ◽  
Rodrigo A. Miranda ◽  
Michio Yamada
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Magnetic Reconnection ◽  
Field Data ◽  
Large Scale ◽  
Physical Characteristics ◽  
Magnetic Field Data ◽  
Current Sheets

AbstractWe apply single- and multi-spacecraft techniques to search for currents sheets in the solar wind during the ICME event of 21 January 2005, using the Cluster magnetic field data. Two large-scale currents sheets are detected at the leading boundary of the ICME ejecta using the single-spacecraft technique, which exhibit physical characteristics typical of magnetic reconnection exhausts in the solar wind.

scholarly journals Solar wind interaction with the Earth's magnetosphere: the role of reconnection in the presence of a large scale sheared flow

2009 ◽  
Vol 16 (1) ◽  
pp. 1-10 ◽  
Author(s):  
F. Califano ◽  
M. Faganello ◽  
F. Pegoraro ◽  
F. Valentini
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Magnetic Reconnection ◽  
Large Scale ◽  
Initial Conditions ◽  
Magnetic Layer ◽  
Magnetic Islands ◽  
Solar Wind Interaction ◽  
Earth’S Magnetosphere ◽  
Earth's Magnetosphere

Abstract. The Earth's magnetosphere and solar wind environment is a laboratory of excellence for the study of the physics of collisionless magnetic reconnection. At low latitude magnetopause, magnetic reconnection develops as a secondary instability due to the stretching of magnetic field lines advected by large scale Kelvin-Helmholtz vortices. In particular, reconnection takes place in the sheared magnetic layer that forms between adjacent vortices during vortex pairing. The process generates magnetic islands with typical size of the order of the ion inertial length, much smaller than the MHD scale of the vortices and much larger than the electron inertial length. The process of reconnection and island formation sets up spontaneously, without any need for special boundary conditions or initial conditions, and independently of the initial in-plane magnetic field topology, whether homogeneous or sheared.

scholarly journals Switchback-like structures observed by Solar Orbiter

2021 ◽  
Author(s):  
Andrey Fedorov ◽  
Philippe Louarn ◽  
Christopher Owen ◽  
Lubomir Prech ◽  
Timothy Horbury ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Distribution Function ◽  
Field Data ◽  
Solar Wind Plasma ◽  
Time Interval ◽  
Ion Distribution ◽  
Time Intervals ◽  
Radial Magnetic Field ◽  
Magnetic Field Data

<p>During 27th September 2020 NASA Parker Solar Probe (PSP) and ESA-NASA Solar Orbiter (SolO) have been located around the same Carrington longitude and their latitudinal separation was very small as well. Solar wind plasma and magnetic field data obtained throughout this time interval  allows to consider that sometimes the solar wind, observed by both spacecrafts, originates from the same coronal hole region. Inside these time intervals the SolO radial magnetic field experiences several short variations similar to the "switchbacks" regularly observed by PSP. We used the SolO SWA-PAS proton analyzer data to analyze the ion distribution function variations inside such switchback-like events to understand if such events are really "remains" of the alfvenic structures observed below 60 Rs.</p>

scholarly journals The solar wind angular-momentum flux observed during Solar Orbiter's first orbit

2021 ◽  
Author(s):  
Daniel Verscharen ◽  
David Stansby ◽  
Adam Finley ◽  
Christopher Owen ◽  
Timothy Horbury ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Angular Momentum ◽  
Momentum Flux ◽  
Large Scale ◽  
Magnetic Field Data ◽  
Proton Data ◽  
Scale Properties ◽  
Orbiter Mission

<p>The Solar Orbiter mission is currently in its cruise phase, during which the spacecraft's in-situ instrumentation measures the solar wind and the electromagnetic fields at different heliocentric distances. </p><p>We evaluate the solar wind angular-momentum flux by combining proton data from the Solar Wind Analyser (SWA) Proton-Alpha Sensor (PAS) and magnetic-field data from the Magnetometer (MAG) instruments on board Solar Orbiter during its first orbit. This allows us to evaluate the angular momentum in the protons in addition to that stored in magnetic-field stresses, and compare these to previous observations from other spacecraft. We discuss the statistical properties of the angular-momentum flux and its dependence on solar-wind properties. </p><p>Our results largely agree with previous measurements of the solar wind’s angular-momentum flux in the inner heliosphere and demonstrate the potential for future detailed studies of large-scale properties of the solar wind with the data from Solar Orbiter.</p>

scholarly journals Dynamics of Variable Dusk-Dawn Flow Associated with Magnetotail Current Sheet Flapping

2021 ◽  
Author(s):  
James Henry Lane ◽  
Adrian Grocott ◽  
Nathan Anthony Case ◽  
Maria-Theresia Walach
Keyword(s):  
Magnetic Field ◽  
Current Sheet ◽  
Field Data ◽  
Large Scale ◽  
Magnetic Field Data ◽  
Analysis Technique ◽  
Upstream Solar Wind ◽  
Magnetotail Dynamics ◽  
Magnetotail Current Sheet

Abstract. Previous observations have provided a clear indication that the dusk-dawn (v⊥y) sense of both slow (< 200 km s−1) and fast (> 200 km s−1) convective magnetotail flows is strongly governed by the Interplanetary Magnetic Field (IMF) By conditions. The related “untwisting hypothesis” of magnetotail dynamics is commonly invoked to explain this dependence, in terms of a large-scale magnetospheric asymmetry. In the current study, we present Cluster spacecraft observations from 12 October 2006 of earthward convective magnetotail plasma flows whose dusk-dawn sense disagrees with the untwisting hypothesis of IMF By control of the magnetotail flows. During this interval, observations of the upstream solar wind conditions from OMNI, and ionospheric convection data using SuperDARN, indicate a large-scale magnetospheric morphology consistent with positive IMF By penetration into the magnetotail. Inspection of the in-situ Cluster magnetic field data reveals a flapping of the magnetotail current sheet; a phenomenon known to influence dusk-dawn flow. Results from the curlometer analysis technique suggest that the dusk-dawn flow perturbations may have been driven by the J x B force associated with a dawnward-propagating flapping of the magnetotail current sheet, locally overriding the expected IMF By control of the flows. We conclude that invocation of the untwisting hypothesis may be inappropriate when interpreting intervals of dynamic magnetotail behaviour such as during current sheet flapping.

scholarly journals Statistical dependence of auroral ionospheric currents on solar wind and geomagnetic parameters from 5 years of CHAMP satellite data

2009 ◽  
Vol 27 (3) ◽  
pp. 1005-1017 ◽  
Author(s):  
L. Juusola ◽  
K. Kauristie ◽  
O. Amm ◽  
P. Ritter
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Field Data ◽  
Dynamic Pressure ◽  
Auroral Oval ◽  
Solar Wind Dynamic Pressure ◽  
Total Field ◽  
Magnetic Field Data ◽  
Champ Satellite ◽  
Field Aligned Current

Abstract. The effects of the solar wind dynamic pressure (P), the z component of the solar wind magnetic field (Bz), the merging electric field (Em), season and the Kp index on R1 and R2 field-aligned currents are studied statistically using magnetic field data from the CHAMP satellite during 2001–2005. The ionospheric and field-aligned currents are determined from the magnetic field data by the recently developed 1-D Spherical Elementary Current System (SECS) method. During southward IMF, increasing |Bz| is observed to clearly increase the total field-aligned current, while during northward IMF, the amount of field-aligned current remains fairly constant regardless of |Bz|. The dependence of the field-aligned current on Bz is given by |Ir[MA]|=0.054·Bz[nT]2−0.34·Bz[nT]+2.4. With increasing P, the intensity of the field-aligned current is also found to increase according to |Ir[MA]|=0.62·P[nPa]+1.6, and the auroral oval is observed to move equatorward. Increasing Em produces similar behaviour, described by |Ir[MA]|=1.41·Em[mV/m]+1.4. While the absolute intensity of the ionospheric current is stronger during negative than during positive Bz, the relative change in the intensity of the currents produced by a more intense solar wind dynamic pressure is observed to be approximately the same regardless of the Bz direction. Increasing Kp from 0 to ≥5 widens the auroral oval and moves it equatorward from between 66°–74° AACGM latitude to 59°–71° latitude. The total field aligned current as a function of Kp is given by |Ir[MA]|=1.1·Kp+0.6. In agreement with previous studies, total field-aligned current in the summer is found to be 1.4 times stronger than in the winter.

scholarly journals Magnetopause reconnection and interlinked flux tubes

2013 ◽  
Vol 31 (10) ◽  
pp. 1853-1866 ◽  
Author(s):  
F. R. Cardoso ◽  
W. D. Gonzalez ◽  
D. G. Sibeck ◽  
M. Kuznetsova ◽  
D. Koga
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Magnetic Reconnection ◽  
Large Scale ◽  
Time Dependent ◽  
Mhd Simulation ◽  
Flux Tubes ◽  
Magnetic Structures ◽  
Mhd Simulations ◽  
Magnetopause Reconnection

Abstract. Magnetic reconnection can be a continuous or a transient process. Global magnetohydrodynamics (MHD) simulations are important tools to understand the relevant magnetic reconnection mechanisms and the resulting magnetic structures. We have studied magnetopause reconnection using a global 3-D MHD simulation in which the interplanetary magnetic field (IMF) has been set to large positive By and large negative Bz components, i.e., a south-duskward direction. Flux tubes have been observed even during these constant solar wind conditions. We have focused on the interlinked flux tubes event resulting from time-dependent, patchy and multiple reconnection. At the event onset, two reconnection modes seem to occur simultaneously: a time-dependent, patchy and multiple reconnection for the subsolar region; and, a steady and large-scale reconnection for the regions far from the subsolar site.

scholarly journals Large-Scale Magnetic Field Structure at the Earth's Orbit, Its Correlation with Solar Activity and Orientation and Motion of the Solar System in the Galaxy

1980 ◽  
Vol 91 ◽  
pp. 167-172
Author(s):  
G. J. Vassilyeva ◽  
M. A. Kuznetsova ◽  
L. M. Kotlyar
Keyword(s):  
Magnetic Field ◽  
Solar Activity ◽  
Solar System ◽  
Interplanetary Magnetic Field ◽  
Field Data ◽  
Large Scale ◽  
Field Structure ◽  
Magnetic Field Data ◽  
Large Scale Magnetic Field ◽  
The Galaxy

Interplanetary magnetic field data from the different satellites obtained during the period 1963-1973 at 1 A.U. and compiled by J. King have been analysed in heliocentric ecliptic coordinates. The peculiarities of the background interplanetary magnetic field (BIMF) are discussed in relation to the orientation of the solar system in the Galaxy and the variable helioefficiency of the planets. The results of the direct cosmic experiments are evidence of the solar activity being a complex phenomenon of the solar system as a whole.

Sign in / Sign up

Export Citation Format

Share Document