Related papers: Probing Subsurface Flows in Active Region NOAA 121…
In this paper, multiwavelength observations of remote coronal dimmings related to an M1.1 circular-ribbon flare (CRF) in active region (AR) 12434 are reported. The confined flare without a CME was observed by AIA and HMI on board SDO on…
We analyze sunspots rotation and magnetic transients in NOAA AR 11429 during two X-class (X5.4 and X1.3) flares using the data from the Helioseismic and Magnetic Imager on board the \emph{Solar Dynamics Observatory}. A large leading sunspot…
Using a recently suggested magneto-morphological classification (MMC, Abramenko, 2021, MNRAS Vol 507) of solar active regions (ARs), we explored 3048 ARs, observed from12 May 1996 to 27 December 2021. Magnetograms were acquired with the…
The solar magnetic field is responsible for all aspects of solar activity. Sunspots are the main manifestation of the ensuing solar activity. Combining high-resolution and synoptic observations has the ambition to provide a comprehensive…
Using the data on magnetic field maps and continuum intensity for Solar Cycles 23 and 24, we explored 100 active regions (ARs) that produced M5.0 or stronger flares. We focus on the presence/absence of the emergence of magnetic flux in…
Plasma upflows with a Doppler shift exceeding -10 km/s at active region (AR) boundaries are considered potential sources of the nascent slow solar wind. We investigate the driving mechanisms of a pair of coronal upflow regions on the…
Solar active regions (ARs) are crucial for understanding the long-term evolution of solar activities and predicting eruptive phenomena, including solar flares and coronal mass ejections. However, the cycle-dependent properties in the…
During the rising phase of Solar Cycle 24 tremendous activity occurred on the Sun with fast and compact emergence of magnetic flux leading to bursts of flares (C to M and even X-class). We investigate the violent events occurring in the…
We analyzed temporal and periodic behavior of sunspot counts (SSCs) in flaring (C, M, or X class flares), and non-flaring active regions (ARs) for the almost two solar cycles (1996 through 2016). Our main findings are as follows: i) The…
In this paper, we present a comprehensive study of the evolutionary phases of a major M6.6 long duration event (LDE) with special emphasize on its pre-flare phase. The event occurred in NOAA 12371 on 2015 June 22. A remarkable aspect of the…
We present a comprehensive study of a series of recurrent jets that occurred at the periphery of the NOAA active region 12114 on 2014 July 7. These jets were found to share the same source region and exhibited rotational motions as they…
It has been previously observed that narrow lanes of transverse and longitudinal magnetic field with opposite polarity are the site of large solar flares. We performed a comprehensive examination of the stokes asymmetries of active region…
Magnetic flux ropes play a key role in triggering solar flares in the solar atmosphere. In this paper, we investigate the evolution of active region NOAA 12268 within 36 hours from 2015 January 29 to 30, during which a flux rope was formed…
During Solar Cycle 23, some active regions(ARs) produced extremely energetic flares and CMEs. These ARs are expected to be characteristically distinct as compared to dormant ARs and quiet regions (QRs). It would be interesting to identify…
Upflows and downflows at active region (AR) boundaries have been frequently observed with spectroscopic observations at extreme ultraviolet (EUV) passbands. In this paper, we report the coexistence of upflows and downflows at the AR…
We study the active region NOAA 10960, which produces two flare events (B5.0, M8.9) on 04 June 2007. We find the observational signature of right handed helical twists in the loop system associated with this active region. The first B5.0…
Using magnetographic data provided by the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory, we analyzed the structure of magnetic fields and vertical electric currents in six active regions (ARs) with different level…
Active regions (ARs) are the main sources of variety in solar dynamic events. Automated detection and identification tools need to be developed for solar features for a deeper understanding of the solar cycle. Of particular interest here…
The evolution of photospheric flow and magnetic fields before and after flares can provide important information regarding the flare triggering and back reaction processes. However, such studies on the flow field are rare due to the paucity…
We investigated the initiation and the evolution of an X7.1-class solar flare observed in solar active region NOAA 13842 on October 1, 2024, based on a data-constrained magnetohydrodynamic (MHD) simulation. The nonlinear force-free field…