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 Solar cycle-related variation in solar differential rotation and meridional flow in solar cycle 24

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Shinsuke Imada ◽  
Kengo Matoba ◽  
Masashi Fujiyama ◽  
Haruhisa Iijima
Keyword(s):  
Solar Cycle ◽  
Differential Rotation ◽  
Feature Tracking ◽  
Middle Latitude ◽  
Meridional Flow ◽  
Magnetic Element ◽  
Solar Dynamics Observatory ◽  
Solar Cycle 24 ◽  
Solar Dynamics ◽  
Cycle 24

AbstractWe studied temporal variation of the differential rotation and poleward meridional circulation during solar cycle 24 using the magnetic element feature tracking technique. We used line-of-sight magnetograms obtained using the helioseismic and magnetic imager aboard the Solar Dynamics Observatory from May 01, 2010 to March 26, 2020 (for almost the entire period of solar cycle 24, Carrington rotation from 2096 to 2229) and tracked the magnetic element features every 1 h. We also estimated the differential rotation and poleward meridional flow velocity profiles. The observed profiles are consistent with those of previous studies on different cycles. Typical properties resulting from torsional oscillations can also be observed from solar cycle 24. The amplitude of the variation was approximately ±10 m s$$^{-1}$$ - 1 . Interestingly, we found that the average meridional flow observed in solar cycle 24 is faster than that observed in solar cycle 23. In particular, during the declining phase of the cycle, the meridional flow of the middle latitude is accelerated from 10 to 17 m s$$^{-1}$$ - 1 , which is almost half of the meridional flow itself. The faster meridional flow in solar cycle 24 might be the result of the weakest cycle during the last 100 years.

scholarly journals Solar Cycle Related Variation in Solar Differential Rotation and Meridional Flow in Cycle 24

2020 ◽  
Author(s):  
Shinsuke Imada ◽  
Kengo Matoba ◽  
Masashi Fujiyama ◽  
Haruhisa Iijima
Keyword(s):  
Solar Cycle ◽  
Differential Rotation ◽  
Middle Latitude ◽  
Meridional Flow ◽  
Magnetic Element ◽  
Solar Dynamics Observatory ◽  
Solar Cycle 24 ◽  
Solar Dynamics ◽  
Cycle 24 ◽  
Pm 10

Abstract We studied temporal variation of the differential rotation and poleward meridional circulation during solar cycle 24 using the magnetic element feature tracking technique. We used line-of-sight magnetograms obtained using the Helioseismic and Magnetic Imager aboard the Solar Dynamics Observatory from May 01, 2010 to March 26, 2020 (for almost the entire period of solar cycle 24, Carrington Rotation from 2096 to 2229) and tracked the magnetic element features every 1 hour. We also estimated the differential rotation and poleward meridional flow velocity profiles. The observed profiles are consistent with those of previous studies on different cycles. Typical properties resulting from torsional oscillations can also be observed from solar cycle 24. The amplitude of the variation was approximately $\pm$10 m s$^{-1}$. Interestingly, we found that the average meridional flow observed in solar cycle 24 is faster than that observed in solar cycle 23. In particular, during the declining phase of the cycle, the meridional flow of the middle latitude is accelerated from 10 to 17 m s$^{-1}$, which is almost half of the meridional flow itself. The faster meridional flow in solar cycle 24 might be the result of the weakest cycle during the last 100 years.

scholarly journals Solar Cycle Related Variation in Solar Differential Rotation and Meridional Flow in Cycle 24

2020 ◽  
Author(s):  
Shinsuke Imada ◽  
Kengo Matoba ◽  
Masashi Fujiyama ◽  
Haruhisa Iijima
Keyword(s):  
Solar Cycle ◽  
Differential Rotation ◽  
Middle Latitude ◽  
Meridional Flow ◽  
Magnetic Element ◽  
Solar Dynamics Observatory ◽  
Solar Cycle 24 ◽  
Solar Dynamics ◽  
Cycle 24 ◽  
Pm 10

Abstract We studied temporal variation of the differential rotation and poleward meridional circulation during solar cycle 24 using the magnetic element feature tracking technique. We used line-of-sight magnetograms obtained using the Helioseismic and Magnetic Imager aboard the Solar Dynamics Observatory from May 01, 2010 to March 26, 2020 (for almost the entire period of solar cycle 24, Carrington Rotation from 2096 to 2229) and tracked the magnetic element features every 1 hour. We also estimated the differential rotation and poleward meridional flow velocity profiles. The observed profiles are consistent with those of previous studies on different cycles. Typical properties resulting from torsional oscillations can also be observed from solar cycle 24. The amplitude of the variation was approximately $\pm$10 m s$^{-1}$. Interestingly, we found that the average meridional flow observed in solar cycle 24 is faster than that observed in solar cycle 23. In particular, during the declining phase of the cycle, the meridional flow of the middle latitude is accelerated from 10 to 17 m s$^{-1}$, which is almost half of the meridional flow itself. The faster meridional flow in solar cycle 24 might be the result of the weakest cycle during the last 100 years.

scholarly journals Solar Cycle Related Variation in Solar Differential Rotation and Meridional Flow in Solar Cycle 24

2020 ◽  
Author(s):  
Shinsuke Imada ◽  
Kengo Matoba ◽  
Masashi Fujiyama ◽  
Haruhisa Iijima
Keyword(s):  
Solar Cycle ◽  
Differential Rotation ◽  
Feature Tracking ◽  
Middle Latitude ◽  
Meridional Flow ◽  
Magnetic Element ◽  
Solar Dynamics Observatory ◽  
Solar Cycle 24 ◽  
Solar Dynamics ◽  
Cycle 24

Abstract We studied temporal variation of the differential rotation and poleward meridional circulation during solar cycle 24 using the magnetic element feature tracking technique. We used line-of-sight magnetograms obtained using the Helioseismic and Magnetic Imager aboard the Solar Dynamics Observatory from May 01, 2010 to March 26, 2020 (for almost the entire period of solar cycle 24, Carrington Rotation from 2096 to 2229) and tracked the magnetic element features every 1 hour. We also estimated the differential rotation and poleward meridional flow velocity profiles. The observed profiles are consistent with those of previous studies on different cycles. Typical properties resulting from torsional oscillations can also be observed from solar cycle 24. The amplitude of the variation was approximately ±10 m s−1. Interestingly, we found that the average meridional flow observed in solar cycle 24 is faster than that observed in solar cycle 23. In particular, during the declining phase of the cycle, the meridional flow of the middle latitude is accelerated from 10 to 17 m s−1, which is almost half of the meridional flow itself. The faster meridional flow in solar cycle 24 might be the result of the weakest cycle during the last 100 years.

scholarly journals Source-region characteristics of anemone active regions in the ascending phase of solar cycle 24

2020 ◽  
Vol 642 ◽  
pp. A233
Author(s):  
R. Sharma ◽  
C. Cid
Keyword(s):  
Magnetic Field ◽  
Solar Cycle ◽  
Minimum Distance ◽  
Source Region ◽  
Coronal Holes ◽  
Active Regions ◽  
Yearly Average ◽  
Solar Cycle 24 ◽  
Cycle 24 ◽  
Rise Phase

Context. Active regions in close proximity to coronal holes, also known as anemone regions, are the best candidates for studying the interaction between closed and open magnetic field topologies at the Sun. Statistical investigation of their source-region characteristics can provide vital clues regarding their possible association with energetic events, relevant from space weather perspectives. Aims. The main goal of our study is to understand the distinct properties of flaring and non-flaring anemone active regions and their host coronal holes, by examining spatial and magnetic field distributions during the rise phase of the solar cycle, in the years 2011–2014. Methods. Anemone regions were identified from the minimum-distance threshold, estimated using the data available in the online catalogs for on-disk active regions and coronal holes. Along with the source-region area and magnetic field characteristics, associated filament and flare cases were also located. Regions with and without flare events were further selected for a detailed statistical examination to understand the major properties of the energetic events, both eruptive and confined, at the anemone-type active regions. Results. Identified anemone regions showed weak asymmetry in their spatial distribution over the solar disk, with yearly average independent from mean sunspot number trend, during the rise phase of solar cycle 24. With the progression in solar cycle, the area and minimum-distance parameters indicated a decreasing trend in their magnitudes, while the magnetic field characteristics indicated an increase in their estimated magnitudes. More than half of the regions in our database had an association with a filament structure, and nearly a third were linked with a magnetic reconnection (flare) event. Anemone regions with and without flares had clear distinctions in their source-region characteristics evident from the distribution of their properties and density analysis. The key differences included larger area and magnetic field magnitudes for flaring anemone regions, along with smaller distances between the centers of the active region and its host coronal hole.

scholarly journals Remeasurement of Solar Observing Optical Network sunspot areas

2020 ◽  
Vol 497 (1) ◽  
pp. 1110-1114
Author(s):  
P J Meadows
Keyword(s):  
United States ◽  
Solar Cycle ◽  
Air Force ◽  
United States Air Force ◽  
Sunspot Group ◽  
Optical Network ◽  
The United States ◽  
Solar Cycle 24 ◽  
Cycle 24

ABSTRACT The United States Air Force solar observing optical network (SOON) sunspot areas have been reported by several researchers over many years to be underestimated by as much as 50 per cent. Here, the areas of sunspots from scanned SOON disc drawings have been accurately remeasured for a period of two months from 2014 October and November – this being near the peak of Solar Cycle 24 and which includes the largest sunspot group of that cycle. The remeasured sunspot areas are now comparable with areas in sunspot catalogues.

scholarly journals Study of Geomagnetic Storms, Interplanetary Magnetic Field and Solar Wind

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Chandrasekhar Bhoj ◽  
Lalan Prasad
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Solar Cycle ◽  
Interplanetary Magnetic Field ◽  
Correlation Coefficient ◽  
Geomagnetic Storms ◽  
Solar Cycle 24 ◽  
Time Periods ◽  
Cycle 24 ◽  
The Imf

The aim of this paper is to investigate the association of the geomagnetic storms with the IMF for solar cycle 24. Result of the present analysis shows that IMF is geoeffective parameter but its impact varies in accordance with different time periods. The correlation coefficient between Dst and IMF found to be -0.6 for solar cycle 24.

scholarly journals Study of Geomagnetic Storms, Interplanetary Magnetic Field and Solar Wind

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Chandrasekhar Bhoj ◽  
Lalan Prasad
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Solar Cycle ◽  
Interplanetary Magnetic Field ◽  
Correlation Coefficient ◽  
Geomagnetic Storms ◽  
Solar Cycle 24 ◽  
Time Periods ◽  
Cycle 24 ◽  
The Imf

The aim of this paper is to investigate the association of the geomagnetic storms with the IMF for solar cycle 24. Result of the present analysis shows that IMF is geoeffective parameter but its impact varies in accordance with different time periods. The correlation coefficient between Dst and IMF found to be -0.6 for solar cycle 24

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