scholarly journals An X-Ray Observations of a Gradual Coronal Mass Ejections (CMEs) on 15th April 2012

2014 ◽  
Vol 27 ◽  
pp. 13-19
Author(s):  
Zety Sharizat Hamidi ◽  
N.N.M. Shariff ◽  
C. Monstein ◽  
W.N.A. Wan Zulkifli ◽  
M.B. Ibrahim ◽  
...  
Keyword(s):  
Active Region ◽  
Coronal Mass Ejections ◽  
Solar Flares ◽  
Solar Observation ◽  
Solar Dynamics Observatory ◽  
Gradual Process ◽  
Solar Filament ◽  
Solar Dynamics ◽  
Important Character ◽  
The Magnetic Field

In the present work, we will highlight the solar observation during 15th April 2012, solar filament eruption which is accompanied by an intense and gradual Coronal Mass Ejections (CMEs). The explosion of CMEs was observed at 2:12:06 UT and also can be observed by the Solar Dynamics Observatory (SDO) with an Active Region AR1458 is crackling with C-class solar flares. The solar flare class B3 and C2 were observed beginning 2241 UT and 0142 UT. The event is considered as second largest CMEs been detected since five years. Although the solar activity within a few days is considered quite low and there are no proton events were observed at geosynchronous orbit., the is still an unexpected explosion of CMEs can be occurred. The radio flux number (10.7 cm) exceeds 102 with the number of sunspot and area of sunspot increased to 77 and 270. The velocity of CMEs was calculated based on the LASCO2 data. From the results, it is clearly seen that the range of the velocity is between 200 kms-1 to 2000 kms-1. This wide of range proved that the mechanism of the CMEs is a gradual process. The explosion of CMEs velocity is located from 80º - 255º from North of the Sun. We can then conclude that currently, the rearrangement of the magnetic field, and solar flares may result in the formation of a shock that accelerates particles ahead of the CMEs loop and an active region play an important character in this event.

scholarly journals Long-term evolution of magnetic fields in flaring Active Region NOAA 12673

2022 ◽  
Vol 21 (12) ◽  
pp. 312
Author(s):  
Johan Muhamad ◽  
Muhamad Zamzam Nurzaman ◽  
Tiar Dani ◽  
Arun Relung Pamutri
Keyword(s):  
Magnetic Field ◽  
Active Region ◽  
Solar Flares ◽  
Long Term Evolution ◽  
Solar Dynamics Observatory ◽  
Active Longitude ◽  
Term Evolution ◽  
Solar Dynamics ◽  
Different Characteristics

Abstract During the lifetime of AR 12673, its magnetic field evolved drastically and produced numerous large flares. In this study, using full maps of the Sun observed by the Solar Dynamics Observatory and the Solar Terrestrial Relations Observatory, we identified that AR 12673 emerged in decayed AR 12665, which had survived for two solar rotations. Although both ARs emerged at the same location, they possessed different characteristics and different flare productivities. Therefore, it is important to study the long-term magnetic evolution of both ARs to identify the distinguishing characteristics of an AR that can produce large solar flares. We used the Space-weather Helioseismic and Magnetic Imager Active Region Patch data to investigate the evolution of the photospheric magnetic field and other physical properties of the recurring ARs during five Carrington rotations. All these investigated parameters dynamically evolved through a series of solar rotations. We compared the long-term evolution of AR 12665 and AR 12673 to understand the differences in their flare-producing properties. We also studied the relation of the long-term evolution of these ARs with the presence of active longitude. We found that the magnetic flux and complexity of AR 12673 developed much faster than those of AR 12665. Our results confirmed that a strong emerging flux that emerged in the pre-existing AR near the active longitude created a very strong and complex AR that produced large flares.

scholarly journals Hot prominence spicules launched from turbulent cool solar prominences

2019 ◽  
Vol 627 ◽  
pp. L5 ◽  
Author(s):  
L. P. Chitta ◽  
H. Peter ◽  
L. Li
Keyword(s):  
Transition Region ◽  
Extreme Ultraviolet ◽  
The Sun ◽  
Solar Dynamics Observatory ◽  
Solar Prominences ◽  
Solar Filament ◽  
Solar Dynamics ◽  
Ultraviolet Observations ◽  
Hot Corona ◽  
Shed Light

A solar filament is a dense cool condensation that is supported and thermally insulated by magnetic fields in the rarefied hot corona. Its evolution and stability, leading to either an eruption or disappearance, depend on its coupling with the surrounding hot corona through a thin transition region, where the temperature steeply rises. However, the heating and dynamics of this transition region remain elusive. We report extreme-ultraviolet observations of quiescent filaments from the Solar Dynamics Observatory that reveal prominence spicules propagating through the transition region of the filament-corona system. These thin needle-like jet features are generated and heated to at least 0.7 MK by turbulent motions of the material in the filament. We suggest that the prominence spicules continuously channel the heated mass into the corona and aid in the filament evaporation and decay. Our results shed light on the turbulence-driven heating in magnetized condensations that are commonly observed on the Sun and in the interstellar medium.

On the Dynamics of the Largest Active Region of the Solar Cycle 24

2017 ◽  
Vol 13 (S335) ◽  
pp. 32-35
Author(s):  
Ranadeep Sarkar ◽  
Nandita Srivastava ◽  
Sajal Kumar Dhara
Keyword(s):  
Magnetic Field ◽  
Solar Cycle ◽  
Active Region ◽  
Comparative Study ◽  
Lorentz Force ◽  
Sunspot Group ◽  
Solar Dynamics Observatory ◽  
Solar Cycle 24 ◽  
Solar Dynamics ◽  
Cycle 24

AbstractWe have studied the dynamics of the solar active region (AR) NOAA 12192 using full-disc continuum images and the vector magnetograms observed by the Helioseismic and Magnetic Imager (HMI) onboard Solar Dynamics Observatory (SDO). AR 12192 is the largest region of the solar cycle 24. It underwent a noticeable growth and produced 6 X-class, 22 M-class and 53 C-class flares during its disc passage. But the most peculiar fact of this AR is that it was associated with only one CME in spite of producing several X-class flares. In this work, we present the area evolution of this giant sunspot group during the first three rotations when it appeared as AR 12172, AR 12192 and AR 12209, respectively. We have also attempted to make a comparative study of the flare-related photospheric magnetic field and Lorentz force changes for both the eruptive and non-eruptive flares produced by AR 12192.

scholarly journals Topological study of active region 11158

2013 ◽  
Vol 8 (S300) ◽  
pp. 479-480
Author(s):  
Jie Zhao ◽  
Hui Li ◽  
Etienne Pariat ◽  
Brigitte Schmieder ◽  
Yang Guo ◽  
...  
Keyword(s):  
Active Region ◽  
Magnetic Fields ◽  
Free Field ◽  
Three Dimensional ◽  
Projection Data ◽  
Solar Dynamics Observatory ◽  
Equal Area ◽  
Linear Force ◽  
Solar Dynamics ◽  
Force Free Field

AbstractWith the cylindrical equal area (CEA) projection data from the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO), we reconstructed the three-dimensional (3D) magnetic fields in the corona, using a non-linear force-free field (NLFFF) extrapolation method every 12 minutes during five days, to calculate the squashing degree factor Q in the volume. The results show that this AR has an hyperbolic flux tube (HFT) configuration, a typical topology of quadrupole, which is stable even during the two large flares (M6.6 and X2.2 class flares).

scholarly journals Enormous Eruption of 2.2 X-Class Solar Flares on 10th June 2014

2014 ◽  
Vol 36 ◽  
pp. 249-257 ◽  
Author(s):  
Zety Sharizat Hamidi ◽  
N.N.M. Shariff
Keyword(s):  
Active Region ◽  
Solar Flare ◽  
The Sun ◽  
X Rays ◽  
Solar Dynamics Observatory ◽  
Time Data ◽  
High Frequencies ◽  
The North ◽  
Solar Dynamics ◽  
Radio Blackout

The observational of active region emission of the Sun contain an critical answer of the time-dependence of the underlying heating mechanism. In this case, we investigate an X2.2 solar flare from a new Active Region AR2087 on the southeast limb of the Sun. The solar flare peaked in the X-rays is around 11:42 UT. It was found that the snapshot of this event from the Solar Dynamics Observatory (SDO) channel with the GOES X-ray plot overlayed. The flare is very bright causes by a diffraction pattern. We explore a parameter space of heating and coronal loop properties. Based on the wavelength, it shows plasma around 6 million Kelvin. At the same time, data from the NOAA issued an R3 level radio blackout, which is centered on Earth where the Sun is currently overhead at the North Africa region. This temporary blackout is caused by the heating of the upper atmosphere from the flare. The blackout level is now at an R1 and this will soon pass. Other than the temporary radio blackout for high frequencies centered over Africa this event will not have a direct impact on us. Until now, we await more data concerning a possible Coronal Mass Ejections (CMEs) but anything would more than likely not head directly towards Earth. An active region AR2087 just let out an X1.5 flare peaking at 12:52 UT. This shows plasmas with temperatures up to about 10 Million Kelvin. This event is considered one of the massive eruption of the Sun this year.

scholarly journals Photospheric downflows observed with SDO/HMI, HINODE, and an MHD simulation

2021 ◽  
Vol 647 ◽  
pp. A178
Author(s):  
T. Roudier ◽  
M. Švanda ◽  
J. M. Malherbe ◽  
J. Ballot ◽  
D. Korda ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Surface ◽  
Outer Part ◽  
Data Cube ◽  
The Sun ◽  
Solar Dynamics Observatory ◽  
Mhd Simulation ◽  
Quiet Sun ◽  
Solar Dynamics ◽  
The Magnetic Field

Downflows on the solar surface are suspected to play a major role in the dynamics of the convection zone, at least in its outer part. We investigate the existence of the long-lasting downflows whose effects influence the interior of the Sun but also the outer layers. We study the sets of Dopplergrams and magnetograms observed with Solar Dynamics Observatory and Hinode spacecrafts and an magnetohydrodynamic (MHD) simulation. All of the aligned sequences, which were corrected from the satellite motions and tracked with the differential rotation, were used to detect the long-lasting downflows in the quiet-Sun at the disc centre. To learn about the structure of the flows below the solar surface, the time-distance local helioseismology was used. The inspection of the 3D data cube (x, y, t) of the 24 h Doppler sequence allowed us to detect 13 persistent downflows. Their lifetimes lie in the range between 3.5 and 20 h with a sizes between 2″ and 3″ and speeds between −0.25 and −0.72 km s−1. These persistent downflows are always filled with the magnetic field with an amplitude of up to 600 Gauss. The helioseismic inversion allows us to describe the persistent downflows and compare them to the other (non-persistent) downflows in the field of view. The persistent downflows seem to penetrate much deeper and, in the case of a well-formed vortex, the vorticity keeps its integrity to the depth of about 5 Mm. In the MHD simulation, only sub-arcsecond downflows are detected with no evidence of a vortex comparable in size to observations at the surface of the Sun. The long temporal sequences from the space-borne allows us to show the existence of long-persistent downflows together with the magnetic field. They penetrate inside the Sun but are also connected with the anchoring of coronal loops in the photosphere, indicating a link between downflows and the coronal activity. A links suggests that EUV cyclones over the quiet Sun could be an effective way to heat the corona.

The Relationship between the Nonpotential Parameters and Flare Eruptions of Solar Active Region NOAA11283

2014 ◽  
Vol 614 ◽  
pp. 681-684
Author(s):  
Gui Ping Ruan ◽  
Hai Qing Xu
Keyword(s):  
Active Region ◽  
Line Of Sight ◽  
Peak Time ◽  
Solar Dynamics Observatory ◽  
Clockwise Rotation ◽  
Helicity Injection ◽  
Solar Dynamics ◽  
Temporal Profiles ◽  
The Relationship ◽  
Potential Parameters

We investigated the variation of magnetic helicity injection through the photospheric surface of the flare-productive active region 11283 during 5 days. The helicity injection was determined using line-of-sight magnetograms with 12-minute cadence taken by the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO). We found that a mount of positive helicity was injected during the five days corresponding with the rapidly sunspot clockwise rotation. Many flares have been produced by this active region from September 3 to 7, 2011. Among them, three big flares M5.3, X2.1 and X1.8 were observed. Using the vector magnetograms of the HMI with 12 minute cadence, We present temporal profiles of non-potential parameters. We find that the extreme value of twist parameters in the shear region R has correspondence with the flare peak time.

scholarly journals The presence of a systematic error in SDO/HMI data

2018 ◽  
Vol 4 (2) ◽  
pp. 3-10
Author(s):  
Георгий Руденко ◽  
Georgiy Rudenko ◽  
Ирина Дмитриенко ◽  
Irina Dmitrienko
Keyword(s):  
Magnetic Field ◽  
Systematic Error ◽  
Radial Direction ◽  
Disk Center ◽  
Magnetic Data ◽  
Solar Dynamics Observatory ◽  
Simple Method ◽  
Small Grains ◽  
Solar Dynamics ◽  
The Magnetic Field

In this paper, we came to the conclusion that there is a systematic error in SDO/HMI (Helioseismic and Magnetic Imager aboard the Solar Dynamics Observatory) vector magnetic data, which reveals itself in a deviation from the radial direction of the knot mag-netic fields manifesting themselves on magnetograms in the form of small grains in a strong magnetic field. This deviation demonstrates a dependence on the distance to the disk center, which cannot be a property of the magnetic field – it can only be artificially introduced into the data. We suggest a simple method for correcting vector magnetograms, which eliminates the detected systematic error.

scholarly journals Validation of Computed Extreme Ultraviolet Emission Spectra During Solar Flares

2020 ◽  
Author(s):  
Shohei Nishimoto ◽  
Kyoko Watanabe ◽  
Toshiki Kawai ◽  
Shinsuke Imada ◽  
Tomoko Kawate
Keyword(s):  
Solar Flares ◽  
Rise Time ◽  
Extreme Ultraviolet ◽  
Emission Spectra ◽  
Physical Models ◽  
X Rays ◽  
Solar Dynamics Observatory ◽  
Ultraviolet Emission ◽  
Proposed Model ◽  
Solar Dynamics

Abstract X-rays and extreme ultraviolet (EUV) emissions from solar flares rapidly change the physical composition of the Earth’s thermosphere and ionosphere, thereby causing space weather phenomena such as communication failures. To predict the effects of flare emissions on the Earth’s upper atmosphere, numerous empirical and physical models have been developed. We verify the extent of reproducing the flare emission spectra using a one-dimensional hydrodynamic calculation and the CHIANTI atomic database. To verify the proposed model, we use the observed EUV spectra obtained by the extreme ultraviolet variability (EVE) on board the Solar Dynamics Observatory (SDO). We examined the “EUV flare time-integrated irradiance” and “EUV flare line rise time” of the EUV emissions for 21 events by comparing the calculation results of the proposed model and observed EUV spectral data. The proposed model succeeded in reproducing the EUV flare time-integrated irradiance of the Fe VIII 131 Å , Fe XVIII 94 Å, and Fe XX 133 Å, as well as the 55 to 355 Å and 55 to 135 Å bands. For the EUV flare line rise time, there was acceptable correlation between the proposed model estimations and observations for all Fe flare emission lines. These results demonstrate that the proposed model can reproduce the EUV flare emission spectra from the emitting plasma with relatively high formation temperature. This indicates that the physics-based model is effective for the accurate reproduction of EUV spectral flux.

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