Search Publications
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…
Above the Noise: The Search for Periodicities in the Inner Heliosphere
De Moortel, Ineke; Threlfall, James; Conlon, Thomas
Remote sensing of coronal and heliospheric periodicities can provide vital insight into the local conditions and dynamics of the solar atmosphere. We seek to trace long (one hour or longer) periodic oscillatory signatures (previously identified above the limb in the corona by, e.g., Telloni et al. in Astrophys. J.767, 138, 2013) from their origin …
Main Cause of the Poloidal Plasma Motion Inside a Magnetic Cloud Inferred from Multiple-Spacecraft Observations
Wang, Yuming; Shen, Chenglong; Liu, Rui +3 more
Although the dynamical evolution of magnetic clouds (MCs) has been one of the foci of interplanetary physics for decades, only few studies focus on the internal properties of large-scale MCs. Recent work by Wang et al. (J. Geophys. Res.120, 1543, 2015) suggested the existence of the poloidal plasma motion in MCs. However, the main cause of this mo…
An Early Diagnostics of the Geoeffectiveness of Solar Eruptions from Photospheric Magnetic Flux Observations: The Transition from SOHO to SDO
Grechnev, V. V.; Chertok, I. M.; Abunin, A. A.
In our previous articles (Chertok et al. in Solar Phys. 282, 175, 2013; Chertok et al. in Solar Phys. 290, 627, 2015), we presented a preliminary tool for the early diagnostics of the geoeffectiveness of solar eruptions based on the estimate of the total unsigned line-of-sight photospheric magnetic flux in accompanying extreme ultraviolet (EUV) ar…