Search Publications
Variation in Coronal Activity from Solar Cycle 24 Minimum to Maximum Using Three-Dimensional Reconstructions of the Coronal Electron Density from STEREO/COR1
Thompson, William T.; Davila, Joseph M.; Wang, Tongjiang +2 more
Three-dimensional electron density distributions in the solar corona are reconstructed for 100 Carrington rotations (CR 2054 - 2153) during 2007/03 - 2014/08 using the spherically symmetric method from polarized white-light observations with the inner coronagraph (COR1) onboard the twin Solar Terrestrial Relations Observatory (STEREO). These three…
Interplanetary Coronal Mass Ejections Resulting from Earth-Directed CMEs Using SOHO and ACE Combined Data During Solar Cycle 23
Paouris, Evangelos; Mavromichalaki, Helen
In this work a total of 266 interplanetary coronal mass ejections observed by the Solar and Heliospheric Observatory/Large Angle and Spectrometric Coronagraph (SOHO/LASCO) and then studied by in situ observations from Advanced Composition Explorer (ACE) spacecraft, are presented in a new catalog for the time interval 1996 - 2009 covering Solar Cyc…
The Relation Between Magnetic Fields and X-ray Emission for Solar Microflares and Active Regions
Kirichenko, A. S.; Bogachev, S. A.
We present the result of a comparison between magnetic field parameters and the intensity of X-ray emission for solar microflares with Geosynchronous Operational Environmental Satellites (GOES) classes from A0.02 to B5.1. For our study, we used the monochromatic MgXII Imaging Spectroheliometer (MISH), the Full-disk EUV Telescope (FET), and the Sol…
A Helicity-Based Method to Infer the CME Magnetic Field Magnitude in Sun and Geospace: Generalization and Extension to Sun-Like and M-Dwarf Stars and Implications for Exoplanet Habitability
Patsourakos, S.; Georgoulis, M. K.
Patsourakos et al. (Astrophys. J.817, 14, 2016) and Patsourakos and Georgoulis (Astron. Astrophys.595, A121, 2016) introduced a method to infer the axial magnetic field in flux-rope coronal mass ejections (CMEs) in the solar corona and farther away in the interplanetary medium. The method, based on the conservation principle of magnetic helicity, …
Solar Energetic Particle Forecasting Algorithms and Associated False Alarms
Dalla, S.; Walsh, R. W.; Swalwell, B.
Solar energetic particle (SEP) events are known to occur following solar flares and coronal mass ejections (CMEs). However, some high-energy solar events do not result in SEPs being detected at Earth, and it is these types of event which may be termed "false alarms".
Automated Spatiotemporal Analysis of Fibrils and Coronal Rain Using the Rolling Hough Transform
Schad, Thomas
A technique is presented that automates the direction characterization of curvilinear features in multidimensional solar imaging datasets. It is an extension of the Rolling Hough Transform (RHT) technique presented by Clark, Peek, and Putman (Astrophys. J.789, 82, 2014), and it excels at rapid quantification of spatial and spatiotemporal feature o…
Comparative Study of the Three-Dimensional Thermodynamical Structure of the Inner Corona of Solar Minimum Carrington Rotations 1915 and 2081
Frazin, Richard A.; Vásquez, Alberto M.; Nuevo, Federico A. +1 more
Using differential emission measure tomography (DEMT) based on time series of EUV images, we carry out a quantitative comparative analysis of the three-dimensional (3D) structure of the electron density and temperature of the inner corona (r <1.25 R⊙) between two specific rotations selected from the last two solar minima, namely Carr…
Characterizing Solar Energetic Particle Event Profiles with Two-Parameter Fits
Kahler, Stephen W.; Ling, Alan G.
The intensity-time profiles of solar energetic (E >10 MeV) particle (SEP) events observed at 1 AU reflect a number of physical processes involving solar injection and interplanetary transport. In addition to energy spectral and composition studies, SEP intensity-time profiles are the basis for diagnostic timescales needed for describing and mod…
Interplanetary Magnetic Flux Ropes as Agents Connecting Solar Eruptions and Geomagnetic Activities
Marubashi, K.; Cho, K. -S.; Ishibashi, H.
We investigate the solar wind structure for 11 cases that were selected for the campaign study promoted by the International Study of Earth-affecting Solar Transients (ISEST) MiniMax24 Working Group 4. We can identify clear flux rope signatures in nine cases. The geometries of the nine interplanetary magnetic flux ropes (IFRs) are examined with a …
The 26 December 2001 Solar Eruptive Event Responsible for GLE63: III. CME, Shock Waves, and Energetic Particles
Klein, K. -L.; Grechnev, V. V.; Kochanov, A. A. +2 more
The SOL2001-12-26 moderate solar eruptive event (GOES importance M7.1, microwaves up to 4000 sfu at 9.4 GHz, coronal mass ejection (CME) speed 1446 km s−1) produced strong fluxes of solar energetic particles and ground-level enhancement (GLE) of cosmic-ray intensity (GLE63). To find a possible reason for the atypically high proton outco…