scholarly journals Investigation of Coronal Mass Ejections. I. Loop-type with Arcade Flare between the Fixed Legs, and Bubble-type Due to Flare Blast Waves

2001 ◽  
Vol 18 (4) ◽  
pp. 345-350 ◽  
Author(s):  
Y. Uchida ◽  
T. Tanaka ◽  
M. Hata ◽  
R. Cameron
Keyword(s):  
Three Dimensional ◽  
Ultra Violet ◽  
Blast Waves ◽  
Fast Mode ◽  
Slow Mode ◽  
Solar Activity Minimum ◽  
Long Wavelength ◽  
Moreton Wave ◽  
Mass Ejection ◽  
The Waves

AbstractIn this paper, we give arguments that there are two types of coronal mass ejection (CME).The first type of CME discussed here is the ‘loop-type’, whose occurrence is related to an arcade flare somewhere between the footpoints. It was found that there were pre-event magnetic connections between the flare location and the locations of the footpoints of a CME of this type, and that these connections disappeared after the event. This suggests that the footpoints of loop-type CMEs are special prescribed points, and this was verified by the observation that the footpoints do not move in this type of CME.The other type of CME is the ‘bubble-type’, which is associated with the flare blast from explosive flares. We confirmed the association of this type of CME with the so-called EIT (Extreme Ultra-violet Imaging Telescope) waves, but the velocity of expansion of the bubble is twice or more greater than that of the EIT waves depending on events. Although EIT waves were widely considered to be Moreton waves viewed by SoHO/EIT in the solar activity minimum period, recent simultaneous observations of both have revealed that the EIT wave is something different from the Moreton wave, and propagates separately with a velocity less than half that of a Moreton wave.We therefore propose a new overall picture: the bubble-type CMEs are the flare-produced MHD blast waves themselves, whose skirt is identified as a Moreton wave. EIT waves may be interpreted as follows: the slow-mode gas motions from the source cause secondary longwavelength fast-mode waves which are trapped in the “waveguide” in the low corona. The secondary long-wavelength wave in the fast-mode, which is trapped in the low corona, has a slower propagation velocity due to the nature of the waves trapped in a “waveguide”. This trapped wave induces slow-mode motions of the gas through a mode-coupling process in the high chromosphere, where the propagation velocities of the fastand slow-mode waves match.Three-dimensional MHD simulations for these two types of CME are in progress, and are previewed in this paper.

Propagation of magnetodynamic waves into a collisionless current layer

1976 ◽  
Vol 15 (3) ◽  
pp. 389-394 ◽  
Author(s):  
A. Hruška
Keyword(s):  
Magnetic Field ◽  
Current Layer ◽  
Fast Mode ◽  
Slow Mode ◽  
Field Aligned Current ◽  
The Waves

In a layer of magnetic field aligned current, waves corresonding to the slow mode in the limit of no current are absorbed and/or reflected as soon as they enter the layer, while, under certain conditions, the waves corresponding to the fast mode do propagate through the layer.

Observations for the Role of Flux rope Eruption in a Geoeffective Solar Flare

2014 ◽  
Vol 4 (2) ◽  
pp. 555-564
Author(s):  
A.M Aslam
Keyword(s):  
Solar Flare ◽  
Flux Rope ◽  
Magnetic Configuration ◽  
Solar Dynamics Observatory ◽  
Multi Wavelength ◽  
Solar Dynamics ◽  
Halo Coronal Mass Ejection ◽  
Mass Ejection ◽  
The Waves

On September 24, 2011 a solar flare of M 7.1 class was released from the Sun. The flare was observed by most of the space and ground based observatories in various wavebands. We have carried out a study of this flare to understand its causes on Sun and impact on earth. The flare was released from NOAA active region AR 11302 at 12:33 UT. Although the region had already produced many M class flares and one X- class flare before this flare, the magnetic configuration was not relaxed and still continued to evolve as seen from HMI observations. From the Solar Dynamics Observatory (SDO) multi-wavelength (131 Ã…, 171 Ã…, 304 Ã… and 1600Ã…) observations we identified that a rapidly rising flux rope triggered the flare although HMI observations revealed that magnetic configuration did not undergo a much pronounced change. The flare was associated with a halo Coronal Mass Ejection (CME) as recorded by LASCO/SOHO Observations. The flare associated CME was effective in causing an intense geomagnetic storm with minimum Dst index -103 nT. A radio burst of type II was also recorded by the WAVES/WIND. In the present study attempt is made to study the nature of coupling between solar transients and geospace.

scholarly journals Three-dimensional MHD modeling of the solar wind structures associated with 13 December 2006 coronal mass ejection

2009 ◽  
Vol 114 (A10) ◽  
pp. n/a-n/a ◽  
Author(s):  
R. Kataoka ◽  
T. Ebisuzaki ◽  
K. Kusano ◽  
D. Shiota ◽  
S. Inoue ◽  
...  
Keyword(s):  
Solar Wind ◽  
Coronal Mass Ejection ◽  
Three Dimensional ◽  
Mhd Modeling ◽  
Mass Ejection

THREE-DIMENSIONAL POLARIMETRIC CORONAL MASS EJECTION LOCALIZATION TESTED THROUGH TRIANGULATION

2010 ◽  
Vol 712 (1) ◽  
pp. 453-458 ◽  
Author(s):  
Thomas G. Moran ◽  
Joseph M. Davila ◽  
William T. Thompson
Keyword(s):  
Coronal Mass Ejection ◽  
Three Dimensional ◽  
Mass Ejection

scholarly journals Steady streaming confined between three-dimensional wavy surfaces

2010 ◽  
Vol 657 ◽  
pp. 430-455 ◽  
Author(s):  
ROMAIN GUIBERT ◽  
FRANCK PLOURABOUÉ ◽  
ALAIN BERGEON
Keyword(s):  
Numerical Study ◽  
Second Harmonic ◽  
Three Dimensional ◽  
Womersley Number ◽  
Long Wavelength ◽  
Steady Streaming ◽  
Confined Flow ◽  
Wavy Surfaces ◽  
Harmonic Flow ◽  
Arbitrary Amplitude

We present a theoretical and numerical study of three-dimensional pulsatile confined flow between two rigid horizontal surfaces separated by an average gap h, and having three-dimensional wavy shapes with arbitrary amplitude σh where σ ~ O(1), but long-wavelength variations λ, with h/λ ≪ 1. We are interested in pulsating flows with moderate inertial effect arising from the Reynolds stress due to the cavity non-parallelism. We analyse the inertial steady-streaming and the second harmonic flows in a lubrication approximation. The dependence of the three-dimensional velocity field in the transverse direction is analytically obtained for arbitrary Womersley numbers and possibly overlapping Stokes layers. The horizontal dependence of the flow is solved numerically by computing the first two pressure fields of an asymptotic expansion in the small inertial limit. We study the variations of the flow structure with the amplitude, the channel's wavelength and the Womersley number for various families of three-dimensional channels. The steady-streaming flow field in the horizontal plane exhibits a quadrupolar vortex, the size of which is adjusted to the cavity wavelength. When increasing the wall amplitude, the wavelengths characterizing the channel or the Womersley number, we find higher-order harmonic flow structures, the origin of which can either be inertially driven or geometrically induced. When some of the channel symmetries are broken, a steady-streaming current appears which has a quadratic dependence on the pressure drop, the amplitude of which is linked to the Womersley number.

Tunable luminescence and white light emission of porphyrin-zinc coordination assemblies

2018 ◽  
Vol 22 (09n10) ◽  
pp. 821-830 ◽  
Author(s):  
Zheng Wang ◽  
Jian-Hua Zhang ◽  
Cheng-Yi Zhu ◽  
Shao-Yun Yin ◽  
Mei Pan
Keyword(s):  
White Light ◽  
Light Emission ◽  
Three Dimensional ◽  
White Light Emission ◽  
Molar Ratio ◽  
Excitation Wavelength ◽  
Temperature Dependent ◽  
Long Wavelength ◽  
Linear Formula ◽  
Zinc Coordination

Bipodal ligand 5,15-bis(4-carboxyphenyl) porphyrin (H[Formula: see text]DCPP) was designed and synthesized. By adjusting the molar ratio of H[Formula: see text]DCPP, ancillary ligand 4,4-bipyridine (bpy) and zinc acetate salts, three novel coordination assemblies, namely, zero-dimensional dimeric [Zn[Formula: see text](H[Formula: see text]DCPP)[Formula: see text] ·bpy] ·4H[Formula: see text]O ·4DMF (Zn-D), two-dimensional polymeric {[Zn[Formula: see text](DCPP) ·bpy[Formula: see text] ·H[Formula: see text]O ·DMF[Formula: see text]] ·solvent}[Formula: see text] (Zn-2D), and three-dimensional polymeric [Zn[Formula: see text](DCPP) ·bpy[Formula: see text]][Formula: see text] (Zn-3D) were assembled. Due to the delicate integration of multiple chromophores in the coordination space combining bpy, DCPP and MLCT emissions together, photoluminescence (PL) of the three porphyrin-zinc coordination assemblies differ from each other and color tone is tunable from blue to orange with changes of the excitation wavelength. In particular, white light emission (WLE) can be observed by the excitation of 270 to 290 nm, representing the first examples of single component WLE compounds based on porphyrin ligands. Furthermore, temperature-dependent luminescence results in a linear [Formula: see text]–[Formula: see text] relationship in Zn-2D and Zn-3D assemblies, applicable for long wavelength red-emitting thermometers.

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