Related papers: Magnetic fields beneath active region coronal loop…
Active regions often host large-scale gas flows in the chromosphere presumably directed along curved magnetic field lines. Spectropolarimetric observations of these flows are critical to understanding the nature and evolution of their…
Nanoflares are regarded as one of the major mechanisms of magnetic energy release and coronal heating in the solar outer atmosphere. We conduct a statistical study on the response of the chromosphere and transition region to nanoflares, as…
Despite decades of studying the Sun, the coronal heating problem remains unsolved. One fundamental issue is that we do not know the spatial scale of the coronal heating mechanism. At a spatial resolution of 1000 km or more it is likely that…
Simultaneous measurement of line-of-sight (LOS) magnetic and velocity fields at the photosphere and chromosphere are presented. Fe I line at $\lambda6569$ and $H_{\alpha}$ at $\lambda6563$ are used respectively for deriving the physical…
We investigate the recently quantified misalignment of $\alpha_{mis} \approx 20^\circ-40^\circ$ between the 3-D geometry of stereoscopically triangulated coronal loops observed with STEREO/EUVI (in four active regions) and theoretical…
Multiscale topological complexity of solar magnetic field is among the primary factors controlling energy release in the corona, including associated processes in the photospheric and chromospheric boundaries. We present a new approach for…
New instruments sensitive to chromospheric radiation at X-ray, UV, Visible, IR, and sub-mm wavelengths have become available that significantly enhance our ability to understand the bi-directional flow of energy through the chromosphere. We…
Internetwork (IN) magnetic fields are highly dynamic, short-lived magnetic structures that populate the interior of supergranular cells. Since they emerge all over the Sun, these small-scale fields bring a substantial amount of flux, and…
Context. A proper estimate of the chromospheric magnetic fields is believed to improve modelling of both active region and coronal mass ejection evolution. Aims. We investigate the similarity between the chromospheric magnetic field…
It is extremely difficult to simulate the details of coronal heating and also make meaningful predictions of the emitted radiation. Thus, testing realistic models with observations is a major challenge. Observational signatures of coronal…
We have carried out numerical simulation based on the equations of radiation magnetohydrodynamics to study the interaction of solar granules and small-scale magnetic fields in photospheric regions with various magnetic fluxes. Four…
We estimated the accuracy of coronal magnetic fields derived from radio observations by comparing them to potential field calculations and the DEM measurements using EUV observations. We derived line of sight component of the coronal…
In the quiet solar photosphere, the mixed polarity fields form a magnetic carpet, which continuously evolves due to dynamical interaction between the convective motions and magnetic field. This interplay is a viable source to heat the solar…
State-of-the-art solar instrumentation is revealing magnetic activity of the Sun with unprecedented resolution. Observations with the 1.6m New Solar Telescope of the Big Bear Solar Observatory are making next steps in our understanding of…
The outer atmosphere of the Sun is composed of plasma heated to temperatures well in excess of the visible surface. We investigate short cool and warm (<1 MK) loops seen in the core of an active region to address the role of field-line…
Differential rotation is the basis of the solar dynamo theory. Synoptic maps of He I intensity from Carrington rotations 2032 to 2135 are utilized to investigate the differential rotation of the solar chromosphere in the He I absorption…
The energy that heats the magnetically closed solar corona originates in the complex motions of the massive photosphere. Turbulent photospheric convection slowly displaces the footpoints of coronal field lines, causing them to become…
The coronal heating problem remains one of the most challenging questions in solar physics. The energy driving coronal heating is widely understood to be associated with convective motions below the photosphere. Recent high-resolution…
Adopting the thermal free-free emission mechanism, the coronal and chromospheric magnetic fields are derived from the polarization and spectral observations with the Nobeyama Radioheliograph at 1.76 cm. The solar active regions (AR) located…
Spicules have been proposed as significant contributors to the mass and energy balance of the corona. While previous observations have provided a glimpse of short-lived transient brightenings in the corona that are associated with spicules,…