Search Publications
Review of Image Quality Measures for Solar Imaging
Popowicz, Adam; Bernacki, Krzysztof; Orlov, Valeri +1 more
Observations of the solar photosphere from the ground encounter significant problems caused by Earth's turbulent atmosphere. Before image reconstruction techniques can be applied, the frames obtained in the most favorable atmospheric conditions (the so-called lucky frames) have to be carefully selected. However, estimating the quality of images co…
Apparent and Intrinsic Evolution of Active Region Upflows
Janvier, Miho; Baker, Deborah; Démoulin, Pascal +1 more
We analyze the evolution of Fe XII coronal plasma upflows from the edges of ten active regions (ARs) as they cross the solar disk using the Hinode Extreme Ultraviolet Imaging Spectrometer (EIS) to do this. Confirming the results of Démoulin et al. (Sol. Phys.283, 341, 2013), we find that for each AR there is an observed long-term evolution of the …
The 26 December 2001 Solar Eruptive Event Responsible for GLE63. II. Multi-Loop Structure of Microwave Sources in a Major Long-Duration Flare
Kochanov, A. A.; Kiselev, V. I.; Uralov, A. M. +1 more
Our analysis of the observations of the SOL2001-12-26 event, which was related to ground-level enhancement of cosmic-ray intensity GLE63, including microwave spectra and images from the Nobeyama Radioheliograph at 17 and 34 GHz, from the Siberian Solar Radio Telescope at 5.7 GHz, and from the Transition Region and Coronal Explorer in 1600 Å, has l…
The Roles of Reconnected Flux and Overlying Fields in CME Speeds
Welsch, Brian T.; Deng, Minda
Researchers have reported i) correlations of coronal mass ejection (CME) speeds and the total photospheric magnetic flux swept out by flare ribbons in flare-associated eruptive events, and, separately, ii) correlations of CME speeds and more rapid decay, with height, of magnetic fields in potential-field coronal models above eruption sites. Here, …
Comparison of CME and ICME Structures Derived from Remote-Sensing and In Situ Observations
Bothmer, V.; Mrotzek, N.
We present results from the comparison of the near-Sun and in situ analysis of two Earth-directed coronal mass ejections (CMEs) with different 3D orientations and solar source region characteristics. The CME on 14 July 2000, the so-called Bastille Day storm, a well-studied event, was observed from a single-point perspective by the Large Angle and …
High-Resolution Vector Magnetograms of the Sun's Poles from Hinode: Flux Distributions and Global Coronal Modeling
Petrie, Gordon
The Sun's polar fields play a leading role in structuring the large-scale solar atmosphere and in determining the interplanetary magnetic field. They are also believed to supply the seed field for the subsequent solar activity cycle. However, present-day synoptic observations do not have sufficient spatial resolution or sensitivity to diagnose acc…
Rearrangements of Open Magnetic Flux and Formation of Polar Coronal Holes in Cycle 24
Golubeva, E. M.; Mordvinov, A. V.
A method of synoptic map assimilation has been developed to study global rearrangements of open magnetic flux and formation of polar coronal holes (PCHs) in the current cycle. The analysis reveals ensembles of coronal holes (ECHs) that appear within unipolar magnetic regions associated with decaying activity complexes (ACs). The cause-effect relat…
Addendum to: Strength of the Solar Coronal Magnetic Field - A Comparison of Independent Estimates Using Contemporaneous Radio and White-Light Observations
Kumari, Anshu; Ramesh, R.; Kathiravan, C. +1 more
This addendum uses an alternate fit for the electron density distribution N (r ) (see Figure 1) and estimates the coronal magnetic field using the new model. We find that the estimates of the magnetic field are in close agreement using both the models.
Diagnostics of Coronal Bright Points using IRIS, AIA, and HMI Observations
Dwivedi, B. N.; Kayshap, P.
We perform the detailed imaging and spectroscopic analysis of two coronal bright points (CBPs). These CBPs are dominated by bright dots or elongated bright features. Their rapid temporal variations lead to a continuous change in their overall morphology at chromospheric and transition-region (TR) temperatures. A 3D potential magnetic field extrapo…
Relation of CME Speed and Magnetic Helicity in CME Source Regions on the Sun during the Early Phase of Solar Cycles 23 and 24
Cho, K. -S.; Jang, S.; Kim, R. -S. +2 more
To investigate the relations between coronal mass ejection (CME) speed and magnetic field properties measured in the photospheric surface of CME source regions, we selected 22 disk CMEs in the rising and early maximum phases of the current Solar Cycle 24. For the CME speed, we used two-dimensional (2D) projected speed observed by the Large Angle a…