Related papers: Coronal Hole and Solar Global Magnetic Field Evolu…
In recent years the role of space weather forecasting has grown tremendously as our society increasingly relies on satellite dependent technologies. The forecasting of flare and CME related transient geomagnetic storms has become a primary…
Coronal holes are usually defined as dark structures as seen in the extreme ultraviolet and X-ray spectrum which are generally associated with open magnetic field. Deriving reliably the coronal hole boundary is of high interest, as its…
How and where are coronal loops rooted in the solar lower atmosphere? The details of the magnetic environment and its evolution at the footpoints of coronal loops are crucial to understanding the processes of mass and energy supply to the…
We characterize the orientation of polar plumes as a tracer of the large-scale coronal magnetic field configuration. We monitor in particular the north and south magnetic pole locations and the magnetic opening during 2007-2008 and provide…
For the period of 1997-2006, coronal holes detected in the SOHO/EIT 195 $\AA$ full disk calibrated images are used to compute the rotation rates of high latitude and near polar coronal holes and, their latitudinal variation is investigated.…
A coronal hole formed as a result of a quiet-Sun filament eruption close to the solar disk center on 2014 June 25. We studied this formation using images from the Atmospheric Imaging Assembly (AIA), magnetograms from the Helioseismic and…
Coronal hole boundaries are the interfaces between closed and open magnetic field regions in the solar atmosphere. Many fundamental processes take place at these regions, including magnetic reconnection that is responsible for solar wind…
A study of the unbalanced magnetic polarity distribution of 70 coronal holes was performed. Data from the Helioseismic and Magnetic Imager (HMI) were used to examine the photospheric line-of-sight magnetic field ($B_{\mathrm{LOS}}$) beneath…
Coronal loops are plasma structures in the solar atmosphere with temperatures reaching millions of Kelvin, shaped and sustained by the magnetic field. However, their morphology and fundamental nature remain subjects of debate. By studying…
The subject of this study is oscillations in the lower atmosphere in coronal-hole regions, where the conditions are favorable for propagation between the atmospheric layers. Based on spectroscopic observations in photospheric and…
Coronal holes are the coolest and darkest regions of the solar atmosphere, as observed both on the solar disk and above the solar limb. Coronal holes are associated with rapidly expanding open magnetic fields and the acceleration of the…
Detailed study of the solar magnetic field is crucial to understand its generation, transport and reversals. The timing of the reversals may have implications on space weather and thus identification of the temporal behavior of the critical…
We investigate the statistics of 288 low-latitude coronal holes extracted from SDO/AIA-193 filtergrams over the time range 2011/01/01 to 2013/12/31. We analyse the distribution of characteristic coronal hole properties, such as the areas,…
Our aim is to study the photospheric flux distribution of a twisted flux tube that emerges from the solar interior. We also report on the eruption of a new flux rope when the emerging tube rises into a pre-existing magnetic field in the…
We investigate the timescales of evolution of stellar coronae in response to surface differential rotation and diffusion. To quantify this we study both the formation time and lifetime of a magnetic flux rope in a decaying bipolar active…
The meridional circulation of the solar magnetic fields in Solar Cycles 21-24 was considered. Data from both ground-based and space observatories were used. Three types of time-latitude distributions of photospheric magnetic fields and…
In this study, we investigate in detail the photospheric magnetic structure of 98 coronal holes using line-of-sight magnetograms of SDO/HMI, and for a subset of 42 coronal holes using HINODE/SOT G-band filtergrams. We divided the magnetic…
The coronal magnetic field evolution of 20 bipolar active regions (ARs) is simulated from their emergence to decay using the time-dependent nonlinear force-free field method of Mackay et al. A time sequence of cleaned photospheric…
The work is devoted to the study of periodic structures in the magnetic field of the photosphere. The polarity of the Sun's magnetic fields shows cyclicity with periods of 1-3 years, which is possibly due to quasi-biennial variations that…
Measuring the global magnetic field of the solar corona remains exceptionally challenging. The fine-scale density structures observed in white light images taken during Total Solar Eclipses (TSEs) are currently the best proxy for inferring…