Search Publications
Predicting Flares and Solar Energetic Particle Events: The FORSPEF Tool
Papaioannou, A.; Anastasiadis, A.; Kouloumvakos, A. +4 more
A novel integrated prediction system for solar flares (SFs) and solar energetic particle (SEP) events is presented here. The tool called forecasting solar particle events and flares (FORSPEF) provides forecasts of solar eruptive events, such as SFs with a projection to occurrence and velocity of coronal mass ejections (CMEs), and the likelihood of…
Earth-Affecting Coronal Mass Ejections Without Obvious Low Coronal Signatures
Nitta, Nariaki V.; Mulligan, Tamitha
We present a study of the origin of coronal mass ejections (CMEs) that were not accompanied by obvious low coronal signatures (LCSs) and yet were responsible for appreciable disturbances at 1 AU. These CMEs characteristically start slowly. In several examples, extreme ultraviolet (EUV) images taken by the Atmospheric Imaging Assembly onboard the S…
Comprehensive Analysis of the Geoeffective Solar Event of 21 June 2015: Effects on the Magnetosphere, Plasmasphere, and Ionosphere Systems
Fineschi, Silvano; Stangalini, Marco; Bruno, Roberto +34 more
A full-halo coronal mass ejection (CME) left the Sun on 21 June 2015 from active region (AR) NOAA 12371. It encountered Earth on 22 June 2015 and generated a strong geomagnetic storm whose minimum Dst value was −204 nT. The CME was associated with an M2-class flare observed at 01:42 UT, located near disk center (N12 E16). Using satellite data from…
On-Disc Observations of Flux Rope Formation Prior to Its Eruption
Palmerio, E.; van Driel-Gesztelyi, L.; Kilpua, E. K. J. +6 more
Coronal mass ejections (CMEs) are one of the primary manifestations of solar activity and can drive severe space weather effects. Therefore, it is vital to work towards being able to predict their occurrence. However, many aspects of CME formation and eruption remain unclear, including whether magnetic flux ropes are present before the onset of er…
CME Dynamics Using STEREO and LASCO Observations: The Relative Importance of Lorentz Forces and Solar Wind Drag
Vourlidas, Angelos; Subramanian, Prasad; Bothmer, Volker +1 more
We seek to quantify the relative contributions of Lorentz forces and aerodynamic drag on the propagation of solar coronal mass ejections (CMEs). We use Graduated Cylindrical Shell (GCS) model fits to a representative set of 38 CMEs observed with the Solar and Heliospheric Observatory (SOHO) and the Solar and Terrestrial Relations Observatory (STER…
A Statistical Study of CME Properties and of the Correlation Between Flares and CMEs over Solar Cycles 23 and 24
Romano, P.; Zuccarello, F.; Compagnino, A.
We investigated some properties of coronal mass ejections (CMEs), such as speed, acceleration, polar angle, angular width, and mass, using data acquired by the Large Angle Spectrometric Coronagraph (LASCO) onboard the Solar and Heliospheric Observatory (SOHO) from 31 July 1997 to 31 March 2014, i.e. during the Solar Cycles 23 and 24. We used two C…
A Study of the Earth-Affecting CMEs of Solar Cycle 24
Hess, Phillip; Zhang, Jie
Using in situ observations from the Advanced Composition Explorer (ACE), we have identified 70 Earth-affecting interplanetary coronal mass ejections (ICMEs) in Solar Cycle 24. Because of the unprecedented extent of heliospheric observations in Cycle 24 that has been achieved thanks to the Sun Earth Connection Coronal and Heliospheric Investigation…
On Flare-CME Characteristics from Sun to Earth Combining Remote-Sensing Image Data with In Situ Measurements Supported by Modeling
Veronig, Astrid M.; Temmer, Manuela; Dissauer, Karin +4 more
We analyze the well-observed flare and coronal mass ejection (CME) from 1 October 2011 (SOL2011-10-01T09:18) covering the complete chain of effects - from Sun to Earth - to better understand the dynamic evolution of the CME and its embedded magnetic field. We study in detail the solar surface and atmosphere associated with the flare and CME using …
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
We estimated the coronal magnetic field strength (B ) during the 23 July 2016 coronal mass ejection (CME) event using i) the flux rope structure of the CME in the white-light coronagraph images and ii) the band-splitting in the associated type II burst. No models were assumed for the coronal electron density (N (r )) we used in the estimation. The…
VLA Measurements of Faraday Rotation through Coronal Mass Ejections
Kooi, Jason E.; Fischer, Patrick D.; Buffo, Jacob J. +1 more
Coronal mass ejections (CMEs) are large-scale eruptions of plasma from the Sun, which play an important role in space weather. Faraday rotation is the rotation of the plane of polarization that results when a linearly polarized signal passes through a magnetized plasma such as a CME. Faraday rotation is proportional to the path integral through th…