Search Publications
From Coronal Observations to MHD Simulations, the Building Blocks for 3D Models of Solar Flares (Invited Review)
Aulanier, G.; Démoulin, P.; Janvier, M.
Solar flares are energetic events taking place in the Sun's atmosphere, and their effects can greatly impact the environment of the surrounding planets. In particular, eruptive flares, as opposed to confined flares, launch coronal mass ejections into the interplanetary medium, and as such, are one of the main drivers of space weather. After briefl…
Statistical Evidence for Contributions of Flares and Coronal Mass Ejections to Major Solar Energetic Particle Events
Dudok de Wit, T.; Klein, K. -L.; Miteva, R. +2 more
Solar energetic particle (SEP) events are related to flares and coronal mass ejections (CMEs). This work is a new investigation of statistical relationships between SEP peak intensities - deka-MeV protons and near-relativistic electrons - and characteristic quantities of the associated solar activity. We consider the speed of the CME and quantitie…
Interplanetary Propagation Behavior of the Fast Coronal Mass Ejection on 23 July 2012
Temmer, M.; Nitta, N. V.
The fast coronal mass ejection (CME) on 23 July 2012 caused attention because of its extremely short transit time from the Sun to 1 AU, which was shorter than 21 h. In situ data from STEREO-A revealed the arrival of a fast forward shock with a speed of more than 2200 km s−1 followed by a magnetic structure moving with almost 1900 km s
Geometrical Relationship Between Interplanetary Flux Ropes and Their Solar Sources
Marubashi, K.; Cho, K. -S.; Gopalswamy, N. +3 more
We investigated the physical connection between interplanetary flux ropes (IFRs) near Earth and coronal mass ejections (CMEs) by comparing the magnetic field structures of IFRs and CME source regions. The analysis is based on the list of 54 pairs of ICMEs (interplanetary coronal mass ejections) and CMEs that are taken to be the most probable solar…
Extreme Ultra-Violet Spectroscopy of the Lower Solar Atmosphere During Solar Flares (Invited Review)
Milligan, Ryan O.
The extreme ultra-violet (EUV) portion of the solar spectrum contains a wealth of diagnostic tools for probing the lower solar atmosphere in response to an injection of energy, particularly during the impulsive phase of solar flares. These include temperature- and density-sensitive line ratios, Doppler-shifted emission lines, nonthermal broadening…
Reconstruction of Helio-Latitudinal Structure of the Solar Wind Proton Speed and Density
Tokumaru, Munetoshi; Bzowski, Maciej; Swaczyna, Paweł +1 more
The modeling of the heliosphere requires continuous three-dimensional solar wind data. The in-situ out-of-ecliptic measurements are very rare, so that other methods of solar wind detection are needed. We use the remote-sensing data of the solar wind speed from observations of interplanetary scintillation (IPS) to reconstruct spatial and temporal s…
Evolution and Consequences of Interacting CMEs of 9 - 10 November 2012 Using STEREO/SECCHI and In Situ Observations
Srivastava, Nandita; Mishra, Wageesh; Chakrabarty, D.
Understanding the kinematic evolution of coronal mass ejections (CMEs) in the heliosphere is important to estimate their arrival time at Earth. The kinematics of CMEs can change when they interact or collide with each other as they propagate in the heliosphere. In this article, we analyze the collision and post-interaction characteristics of two E…
Geoeffectiveness of Coronal Mass Ejections in the SOHO Era
Rodriguez, L.; Vršnak, B.; Veronig, A. +6 more
The main objective of the study is to determine the probability distributions of the geomagnetic Dst index as a function of the coronal mass ejection (CME) and solar flare parameters for the purpose of establishing a probabilistic forecast tool for the intensity of geomagnetic storms. We examined several CME and flare parameters as well as the eff…
Improved Helioseismic Analysis of Medium-ℓ Data from the Michelson Doppler Imager
Schou, Jesper; Larson, Timothy P.
We present a comprehensive study of one method for measuring various parameters of global modes of oscillation of the Sun. Using velocity data taken by the Michelson Doppler Imager (MDI), we analyze spherical harmonic degrees ℓ ≤300 . Both current and historical methodologies are explained, and the various differences between the two are investiga…
Relations Between Microwave Bursts and Near-Earth High-Energy Proton Enhancements and Their Origin
Grechnev, V. V.; Chertok, I. M.; Kiselev, V. I. +1 more
We further study the relations between parameters of bursts at 35 GHz recorded with the Nobeyama Radio Polarimeters during 25 years and solar proton events (Grechnev et al. in Publ. Astron. Soc. Japan65, S4, 2013a). Here we address the relations between the microwave fluences at 35 GHz and near-Earth proton fluences above 100 MeV to find informati…