The association of Coronal Mass Ejections during solar maximum times with the heliomagnetic current sheet

1993 ◽  
Vol 13 (9) ◽  
pp. 183-186
Author(s):  
B. Mendoza ◽  
R. Pérez-Enríquez
Keyword(s):  
Current Sheet ◽  
Coronal Mass Ejections ◽  
Solar Maximum

Coronal Mass Ejections and Solar Filament Disappearances at Solar Maximum

1994 ◽  
Vol 144 ◽  
pp. 127-129
Author(s):  
S. Dinulescu ◽  
G. Maris
Keyword(s):  
Coronal Mass Ejections ◽  
Solar Maximum ◽  
Solar Filament

AbstractOccurrence of CMEs as a result of solar filament disappearance is discussed over the cycle 22.

Rotation-Averaged Rates of Coronal Mass Ejections and Dynamics of Polar Crown Filaments

1994 ◽  
Vol 144 ◽  
pp. 83-89 ◽  
Author(s):  
E. W. Cliver ◽  
O. C. St. Cyr ◽  
R. A. Howard ◽  
P. S. McIntosh
Keyword(s):  
Solar Cycle ◽  
Current Sheet ◽  
Sunspot Number ◽  
Tilt Angle ◽  
Duty Cycle ◽  
Coronal Mass Ejections ◽  
Solar Minimum ◽  
Heliospheric Current Sheet ◽  
North And South ◽  
Rise Phase

AbstractWe obtained Carrington-rotation-averaged daily rates of coronal mass ejections (CMEs), corrected for duty cycle, for the period 1979-1989. The 27-day averages of CME rate and sunspot number are correlated over this 11-yr period, although significant discrepancies can occur for any given rotation. The baseline CME rate exhibited quasi-discontinuities in 1982 (decrease) and 1988 (increase) when the “tilt angle” of the heliospheric current sheet passed through values of ∼ 50°. We suggest that these quasi-discontinuities are related to the dynamics of the belts of polar crown filaments that reside at ∼ 50° north and south of the equator during solar minimum and move poleward during the rise phase of the solar cycle.

scholarly journals Solar Eruptions - the Effects on the Earth’s Environment

2002 ◽  
Vol 12 ◽  
pp. 384-388
Author(s):  
P. Brekke
Keyword(s):  
Space Weather ◽  
Coronal Mass Ejections ◽  
Solar Maximum ◽  
Space Environment ◽  
The Sun ◽  
Technological Systems ◽  
Heliospheric Observatory ◽  
Time Space ◽  
New Information ◽  
Solar Eruptions

AbstractThe response of our space environment to the constantly changing Sun is known as ”Space Weather”. The Solar and Heliospheric Observatory (SOHO) has obtained significant new information about coronal mass ejections (CMEs), the source of the most severe disturbances in the Earth’s environment. Most of the time space weather is of little concern in our everyday lives. However, when the space environment is disturbed by the variable outputs of the Sun, technologies that we depend on both in orbit and on the ground can be affected. The increasing deployment of radiation-, current-, and field-sensitive technological systems over the last few decades and the increasing presence of complex systems in space combine to make society more vulnerable to solar-terrestrial disturbances. Thus, our society is much more sensitive to space weather activity today compared to the last solar maximum. By observing the Sun 24 hours per day, SOHO has proved to be an important “space weather watchdog”. The importance of real-time monitoring of the Sun will be pointed out and a number of enterprises affected by space weather will be discussed.

scholarly journals The birth of a coronal mass ejection

2019 ◽  
Vol 5 (3) ◽  
pp. eaau7004 ◽  
Author(s):  
Tingyu Gou ◽  
Rui Liu ◽  
Bernhard Kliem ◽  
Yuming Wang ◽  
Astrid M. Veronig
Keyword(s):  
Magnetic Reconnection ◽  
Coronal Mass Ejection ◽  
Current Sheet ◽  
Magnetic Structure ◽  
Coronal Mass Ejections ◽  
Flux Rope ◽  
Evolutionary Path ◽  
X Ray ◽  
Flux Ropes ◽  
Mass Ejection

The Sun’s atmosphere is frequently disrupted by coronal mass ejections (CMEs), coupled with flares and energetic particles. The coupling is usually attributed to magnetic reconnection at a vertical current sheet connecting the flare and CME, with the latter embedding a helical magnetic structure known as flux rope. However, both the origin of flux ropes and their nascent paths toward eruption remain elusive. Here, we present an observation of how a stellar-sized CME bubble evolves continuously from plasmoids, mini flux ropes that are barely resolved, within half an hour. The eruption initiates when plasmoids springing from a vertical current sheet merge into a leading plasmoid, which rises at increasing speeds and expands impulsively into the CME bubble, producing hard x-ray bursts simultaneously. This observation illuminates a complete CME evolutionary path capable of accommodating a wide variety of plasma phenomena by bridging the gap between microscale and macroscale dynamics.

scholarly journals Anomalous-plasmoid-ejection-induced secondary magnetic reconnection: modeling solar flares and coronal mass ejections by laser–plasma experiments

2013 ◽  
Vol 1 (1) ◽  
pp. 11-16 ◽  
Author(s):  
Quanli Dong ◽  
Dawei Yuan ◽  
Shoujun Wang ◽  
Xun Liu ◽  
Yutong Li ◽  
...  
Keyword(s):  
Magnetic Reconnection ◽  
Current Sheet ◽  
Coronal Mass Ejections ◽  
Solar Flares ◽  
Theoretical Models ◽  
High Energy ◽  
High Energy Density ◽  
Driving Mechanism ◽  
Secondary Current ◽  
Field Lines

AbstractThe driving mechanism of solar flares and coronal mass ejections is a topic of ongoing debate, apart from the consensus that magnetic reconnection plays a key role during the impulsive process. While present solar research mostly depends on observations and theoretical models, laboratory experiments based on high-energy density facilities provide the third method for quantitatively comparing astrophysical observations and models with data achieved in experimental settings. In this article, we show laboratory modeling of solar flares and coronal mass ejections by constructing the magnetic reconnection system with two mutually approaching laser-produced plasmas circumfused of self-generated megagauss magnetic fields. Due to the Euler similarity between the laboratory and solar plasma systems, the present experiments demonstrate the morphological reproduction of flares and coronal mass ejections in solar observations in a scaled sense, and confirm the theory and model predictions about the current-sheet-born anomalous plasmoid as the initial stage of coronal mass ejections, and the behavior of moving-away plasmoid stretching the primary reconnected field lines into a secondary current sheet conjoined with two bright ridges identified as solar flares.

Coronal mass ejections observed during the Solar Maximum Mission: Latitude distribution and rate of occurrence

1984 ◽  
Vol 89 (A5) ◽  
pp. 2639 ◽  
Author(s):  
A. J. Hundhausen ◽  
C. B. Sawyer ◽  
L. House ◽  
R. M. E. Illing ◽  
W. J. Wagner
Keyword(s):  
Coronal Mass Ejections ◽  
Solar Maximum ◽  
Solar Maximum Mission ◽  
Latitude Distribution

Association of coronal mass ejections with the heliomagnetic current sheet

1993 ◽  
Vol 98 (A6) ◽  
pp. 9365 ◽  
Author(s):  
Blanca Mendoza ◽  
Román Pérez-Enríquez
Keyword(s):  
Current Sheet ◽  
Coronal Mass Ejections

scholarly journals Observations of radio spectra at 1–2.5 GHz associated with CME start time

2008 ◽  
Vol 4 (S257) ◽  
pp. 317-321
Author(s):  
José R. Cecatto
Keyword(s):  
Radio Emission ◽  
Coronal Mass Ejections ◽  
Solar Radio ◽  
Solar Maximum ◽  
Radio Spectrum ◽  
The Sun ◽  
Radio Bursts ◽  
Start Time ◽  
Trigger Mechanism ◽  
Made In

AbstractWe know Coronal Mass Ejections (CME) and flares are the most energetic phenomena happening on the Sun. Until now the information about origin and trigger mechanism of CMEs remains scarce. Also, there is unconclusive information about the association between them and flares although progress has been made in recent years. Multi-spectral observations suggested that the flare energy release occurs in regions from where the decimetric radio emission originates. In this case, investigations of the solar emission in this wavelength range can give us valuable information about these questions. During last solar maximum the Brazilian Solar Spectroscope (BSS) observed the solar radio spectrum (1–2.5 GHz) with high time (100–20 ms) and frequency (50–100 channels) resolutions on a daily (11–19 UT) basis. A survey during the period 1999–2002, shows that a significant fraction (20% –57 events) of CMEs recorded by LASCO has an association with the spectra of radio bursts recorded by BSS. Analysis of the radio spectrum associated to CME shows there is a dominance of continuum and/or pulsation and that the association becomes stronger when we consider the CME acceleration since its origin on the Sun. A statistics of this association between CME dynamics and the characteristics of decimetric radio bursts recorded by BSS is presented. Emphasis is given to observations of the association with CME start time.

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