Related papers: Active region upflows in various coronal structure…
Solar jets are collimated plasma ejections along magnetic field lines observed in hot (EUV jets) and cool (chromospheric surges) temperature diagnostics. Their trigger mechanisms and the relationship between hot and cool jets are still not…
We study the high frequency dynamics in the braided magnetic structure of an active region (AR 11520) moss as observed by High-Resolution Coronal Imager (Hi-C). We detect quasi periodic flows and waves in these structures. We search for…
We have performed numerical magnetohydrodynamic (MHD) simulations of two closed active regions (AR). The input magnetic field values were the coronal magnetic field computed as extrapolation coronal from observations of the photospheric…
Data for 3046 solar active regions (ARs) observed since May 12, 1996 to December 27, 2021 were utilized to explore how the magnetic fluxes from ARs of different complexity follow the solar cycle. Magnetograms from the Michelson Doppler…
In this Letter we present a seismological detection of a rising motion of magnetic flux in the shallow convection zone of the Sun, and show estimates of the emerging speed and its decelerating nature. In order to evaluate the speed of…
Context: Giant-cell convection is believed to be an important component of solar dynamics. For example, it is expected to play a crucial role in maintaining the Sun's differential rotation. Aims: We re-examine early reports of giant…
We explore the general properties of near-surface flows around solar active regions. Helioseismic holography is applied to HMI Dopplergrams yielding nearly 5000 flow measurements of 336 unique active regions observed by the Solar Dynamics…
A solar active region (AR) is a three-dimensional magnetic structure formed in the convection zone, whose property is fundamentally important for determining the coronal structure and solar activity when emerged. However, our knowledge on…
Outflows perpendicular to the guide field are believed to be a possible signature of magnetic reconnection in the solar corona and specifically a way to detect the occurrence of ubiquitous small-angle magnetic reconnection. The aim of this…
There have been ubiquitous observations of wave-like motions in the solar atmosphere for decades. Recent improvements to space- and ground-based observatories have allowed the focus to shift to smaller magnetic structures on the solar…
Using high-resolution ring analysis (HRRA) we deduce subsurface flows within magnetic active regions and within quiet sun. With this procedure we are capable of measuring flows with a horizontal spatial resolution of 2 degrees in…
Aims. Combining high-resolution and synoptic observations aims to provide a comprehensive description of flux emergence at photospheric level and of the growth process that eventually leads to a mature active region. Methods. Small active…
Bipolar emerging flux regions (EFRs) form active regions (ARs) that generally evolve in a pre-existing magnetic environment in the solar atmosphere. Reconfiguration of the small- and large-scale magnetic connectivities is invoked to explain…
We present the first model that couples the formation of the corona of a solar active region to a model of the emergence of a sunspot pair. This allows us to study when, where, and why active region loops form, and how they evolve. We use a…
Supra-arcade downflows (SADs) are infrequent, wiggly opaque structures observed to descend through the solar corona, mostly in EUV and soft X-ray frequencies. From their physical characteristics, SADs have been interpreted as voided…
Plasma loops or plumes rooted in sunspot umbrae often harbor downflows with speeds of 100 km/s. These downflows are supersonic at transition region temperatures of 0.1 MK. The source of these flows is not well understood. We aim to…
Flares are a major explosive event in our solar system. They are often followed by coronal mass ejection that has a potential to trigger the geomagnetic storms. There are various studies aiming to predict when and where the flares are…
Local helioseismology provides a unique opportunity to investigate the subsurface structure and dynamics of active regions and their effect on the large-scale flows and global circulation of the Sun. We use measurements of plasma flows in…
We present a new computational approach that addresses the difficulty of obtaining the correct interaction between the solar corona and the transition region in response to rapid heating events. In the coupled corona, transition region and…
In this article, the physical processes occurring in the convective layer and the photosphere of the Sun and their connection to the formation of active regions (ARs) and the development of the corresponding magnetic field are explored.…