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Magnetic helicity is a useful quantity in characterizing the magnetic systems of solar active regions. The purpose of the present work is to check for consistency between the local correlation tracking (LCT) method used to measure helicity injection through the photosphere, and the linear force-free field (LFFF) method used to determine helicity in the corona, based on the principle of helicity conservation in the solar corona. We have calculated the amount of magnetic helicity injected through the photosphere during the first disk passage of AR 10696 using the LCT method initially described by Chae. We have also measured the coronal magnetic helicity as a function of time using the LFFF method. With a value for the force-free , the coronal field is constructed from the extrapolation of the Solar and Heliospheric Observatory (SOHO) MDI magnetograms, then compared with the coronal loops in the EUV images taken by the SOHO EIT. The force-free that best fits the loops is used to calculate the coronal helicity. From a careful comparison of different helicity measurements during each time interval, we have reached the core conclusion that our measurements follow the helicity conservation principle with an uncertainty of $15% and hence support the consistency between the two different methods with the same amount of uncertainty. Subject headingg s: Sun: corona -Sun: coronal mass ejections (CMEs) -Sun: magnetic fieldsSun: photosphere

Technical skills of Dr. Yurchyshyn include many-year experience in solar observations with various groundbased solar instruments, substantial experience with acquisition, processing and scientific analysis of space-based observations, and deep physical understanding and broad knowledge of solar phenomena. He actively participated in design and construction of BBSO's full disk Halpha telescope and developed the telescope control and data acquisition software. Managerial performance Dr. Yurchyshyn has organized several successful research teams as evidenced by his full publication list. He also supervised research of several PhD students. For about 5 years and managed the Global Halpha Network. He oversaw network expansion, data flow as well as the network website and maintenance.

It is well-known that light bridges inside a sunspot produce small-scale plasma ejections and transient brightenings in the chromosphere, but the nature and origin of such phenomena are still unclear. Utilizing the high-spatial and hightemporal resolution spectral data taken with the Fast Imaging Solar Spectrograph and the TiO 7057Å broadband filter images installed at the 1.6 meter New Solar Telescope of Big Bear Solar Observatory, we report arcsecond-scale chromospheric plasma ejections (1. ′′ 7) inside a light bridge. Interestingly, the ejections are found to be a manifestation of upwardly propagating shock waves as evidenced by the sawtooth patterns seen in the temporal-spectral plots of the Ca ii 8542Å and Hα intensities. We also found a fine-scale photospheric pattern (1 ′′ ) diverging with a speed of about 2 km s −1 two minutes before the plasma ejections, which seems to be a manifestation of magnetic flux emergence. As a response to the plasma ejections, the corona displayed small-scale transient brightenings. Based on our findings, we suggest that the shock waves can be excited by the local disturbance caused by magnetic reconnection between the emerging flux inside the light bridge and the adjacent umbral magnetic field. The disturbance generates slow-mode waves, which soon develop into shock waves, and manifest themselves as the arcsecond-scale plasma ejections. It also appears that the dissipation of mechanical energy in the shock waves can heat the local corona.

We report on the successive occurrence of 0.″5 wide photospheric vortices with strong transverse shear flows at the edge of a sunspot light bridge (LB), and the subsequent ejection of chromospheric surges observed using a Visible Inteferometry Spectrograph, a broadband TiO filter, and a Near InfRared Imaging Spectrograph of the Goode Solar Telescope operating at Big Bear Solar Observatory. The Hα surges ejected at the location of the vortices often appeared in a hollow cylindrical structure. We also observed quasi-periodic vortex-associated bright Hα plasma blobs moving upward with a speed of up to 4 km s−1. In view of the strong shear flow at the edge of the LB, it is likely that the vortices form under the Kelvin–Helmholtz instability. The surges may result from either the magnetic tension generated after magnetic reconnection or an acoustic impulse of a fast photospheric transverse flow. Otherwise, the surges could also be associated with Alfvénic waves, in which case their origin could be torsional magnetic fields generated in the process of the vortex formation.

Using multi-wavelength observations we studied a slow rise, multi-step X1.6 flare that began on November 7, 2014 as a localized eruption of core fields inside a δ-sunspot and later engulfed the entire active region. This flare event was associated with formation of two systems of post eruption arcades and several J-shaped flare ribbons showing extremely fine details, irreversible changes in the photospheric magnetic fields, and it was accompanied by a fast and wide coronal mass ejection. Data from the Solar Dynamics Observatory, IRIS spacecraft along with the ground based data from the New Solar Telescope (NST) present evidence that i) the flare and the eruption were directly triggered by a flux emergence that occurred inside a δ-sunspot at the boundary between two umbrae; ii) this event represented an example of the formation of an unstable flux rope observed only in hot AIA channels (131 and 94Å) and LASCO C2 coronagraph images; iii) the global post eruption arcade spanned the entire AR and was due to global scale reconnection occurring at heights of about one solar radii, indicating on the global spatial and temporal scale of the eruption.