scholarly journals On the influence of open magnetic flux on substorm intensity: Ground- and space-based observations

2013 ◽  
Vol 118 (6) ◽  
pp. 2958-2969 ◽  
Author(s):  
L. B. N. Clausen ◽  
S. E. Milan ◽  
J. B. H. Baker ◽  
J. M. Ruohoniemi ◽  
K.-H. Glassmeier ◽  
...  
Keyword(s):  
Magnetic Flux ◽  
Open Magnetic Flux

FeNi-based flat magnetoimpedance nanostructures with open magnetic flux: New topological approaches

2015 ◽  
Vol 383 ◽  
pp. 220-225 ◽  
Author(s):  
G.V. Kurlyandskaya ◽  
A.A. Chlenova ◽  
E. Fernández ◽  
K.J. Lodewijk
Keyword(s):  
Magnetic Flux ◽  
Open Magnetic Flux

scholarly journals Aurora and open magnetic flux during isolated substorms, sawteeth, and SMC events

2007 ◽  
Vol 25 (8) ◽  
pp. 1865-1876 ◽  
Author(s):  
A. D. DeJong ◽  
X. Cai ◽  
R. C. Clauer ◽  
J. F. Spann
Keyword(s):  
Magnetic Flux ◽  
Temporal Variations ◽  
Auroral Oval ◽  
Polar Cap ◽  
Expansion Phase ◽  
Magnetospheric Convection ◽  
Open Magnetic Flux ◽  
Open Flux ◽  
The Individual

Abstract. Using Polar UVI LBHl and IMAGE FUV WIC data, we have compared the auroral signatures and polar cap open flux for isolated substorms, sawteeth oscillations, and steady magnetospheric convection (SMC) events. First, a case study of each event type is performed, comparing auroral signatures and open magnetic fluxes to one another. The latitude location of the auroral oval is similar during isolated substorms and SMC events. The auroral intensity during SMC events is similar to that observed during the expansion phase of an isolated substorm. Examination of an individual sawtooth shows that the auroral intensity is much greater than the SMC or isolated substorm events and the auroral oval is displaced equatorward making a larger polar cap. The temporal variations observed during the individual sawtooth are similar to that observed during the isolated substorm, and while the change in polar cap flux measured during the sawtooth is larger, the percent change in flux is similar to that measured during the isolated substorm. These results are confirmed by a statistical analysis of events within these three classes. The results show that the auroral oval measured during individual sawteeth contains a polar cap with, on average, 150% more magnetic flux than the oval measured during isolated substorms or during SMC events. However, both isolated substorms and sawteeth show a 30% decrease in polar cap magnetic flux during the dipolarization (expansion) phase.

scholarly journals Solar wind elemental abundances related to the Sun's open magnetic flux

2009 ◽  
Vol 505 (3) ◽  
pp. 1237-1244 ◽  
Author(s):  
X. Wang ◽  
B. Klecker ◽  
P. Wurz
Keyword(s):  
Solar Wind ◽  
Magnetic Flux ◽  
Elemental Abundances ◽  
Open Magnetic Flux

Meridional Flow and the Solar Cycle Variation of the Sun’s Open Magnetic Flux

2002 ◽  
Vol 580 (2) ◽  
pp. 1188-1196 ◽  
Author(s):  
Y.‐M. Wang ◽  
N. R. Sheeley, Jr. ◽  
J. Lean
Keyword(s):  
Solar Cycle ◽  
Magnetic Flux ◽  
Meridional Flow ◽  
Solar Cycle Variation ◽  
Cycle Variation ◽  
Open Magnetic Flux

scholarly journals A superposed epoch analysis of auroral evolution during substorm growth, onset and recovery: open magnetic flux control of substorm intensity

2009 ◽  
Vol 27 (2) ◽  
pp. 659-668 ◽  
Author(s):  
S. E. Milan ◽  
A. Grocott ◽  
C. Forsyth ◽  
S. M. Imber ◽  
P. D. Boakes ◽  
...  
Keyword(s):  
Magnetic Flux ◽  
Ring Current ◽  
Low Latitude ◽  
Superposed Epoch Analysis ◽  
Before And After ◽  
Open Magnetic Flux ◽  
Open Flux ◽  
Epoch Analysis ◽  
Proton Aurora ◽  
Current Systems

Abstract. We perform two superposed epoch analyses of the auroral evolution during substorms using the FUV instrument on the Imager for Magnetopause-to-Aurora Global Explorer (IMAGE) spacecraft. The larger of the two studies includes nearly 2000 substorms. We subdivide the substorms by onset latitude, a measure of the open magnetic flux in the magnetosphere, and determine average auroral images before and after substorm onset, for both electron and proton aurora. Our results indicate that substorms are more intense in terms of auroral brightness when the open flux content of the magnetosphere is larger, and that magnetic flux closure is more significant. The increase in auroral brightness at onset is larger for electrons than protons. We also show that there is a dawn-dusk offset in the location of the electron and proton aurora that mirrors the relative locations of the region 1 and region 2 current systems. Superposed epoch analyses of the solar wind, interplanetary magnetic field, and geomagnetic indices for the substorms under study indicate that dayside reconnection is expected to occur at a faster rate prior to low latitude onsets, but also that the ring current is enhanced for these events.

scholarly journals Modelling 3D magnetic networks in a realistic solar atmosphere

2019 ◽  
Vol 489 (1) ◽  
pp. 28-35
Author(s):  
Frederick A Gent ◽  
Ben Snow ◽  
Viktor Fedun ◽  
Robertus Erdélyi
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Solar Atmosphere ◽  
Energy Transport ◽  
Solar Dynamics Observatory ◽  
Lower Corona ◽  
Flux Tubes ◽  
Background Magnetic Field ◽  
Magnetic Flux Tubes ◽  
Open Magnetic Flux

ABSTRACT The magnetic network extending from the photosphere (solar radius ≃ R⊙) to the lower corona ($\mathrm{ R}_\odot +10\, {\rm Mm}$) plays an important role in the heating mechanisms of the solar atmosphere. Here we develop further the models of the authors with realistic open magnetic flux tubes, in order to model more complicated configurations. Closed magnetic loops and combinations of closed and open magnetic flux tubes are modelled. These are embedded within a stratified atmosphere, derived from observationally motivated semi-empirical and data-driven models subject to solar gravity and capable of spanning from the photosphere up into the chromosphere and lower corona. Constructing a magnetic field comprising self-similar magnetic flux tubes, an analytic solution for the kinetic pressure and plasma density is derived. Combining flux tubes of opposite polarity, it is possible to create a steady background magnetic field configuration, modelling a solar atmosphere exhibiting realistic stratification. The result can be applied to the Solar and Heliospheric Observatory Michelson Doppler Imager (SOHO/MDI), Solar Dynamics Observatory Helioseismic and Magnetic Imager (SDO/HMI) and other magnetograms from the solar surface, for which photospheric motions can be simulated to explore the mechanism of energy transport. We demonstrate this powerful and versatile method with an application to HMI data.

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