Search Publications
Near-Earth Interplanetary Coronal Mass Ejections During Solar Cycle 23 (1996 - 2009): Catalog and Summary of Properties
Cane, H. V.; Richardson, I. G.
In a previous study (Cane and Richardson, J. Geophys. Res.108(A4), SSH6-1, 2003), we investigated the occurrence of interplanetary coronal mass ejections in the near-Earth solar wind during 1996 - 2002, corresponding to the increasing and maximum phases of solar cycle 23, and provided a "comprehensive" catalog of these events. In this paper, we pr…
Kappa Distributions: Theory and Applications in Space Plasmas
Pierrard, V.; Lazar, M.
The plasma particle velocity distributions observed in the solar wind generally show enhanced (non-Maxwellian) suprathermal tails, decreasing as a power law of the velocity and well described by the family of Kappa distribution functions. The presence of non-thermal populations at different altitudes in space plasmas suggests a universal mechanism…
Observation of Plasma Instabilities in Quiescent Prominences
Title, A.; Berger, T.; Frank, Z. +2 more
We study dynamics of quiescent prominences using several data sets taken with the Solar Optical Telescope (SOT) on Hinode. We find a number of processes occurring at different stages of prominence evolution that are common for all of our chosen cases and, having universal character, can be related to fundamental plasma instabilities. We combine th…
Modeling the Subsurface Structure of Sunspots
Strassmeier, K. G.; Thompson, M. J.; Komm, R. +19 more
While sunspots are easily observed at the solar surface, determining their subsurface structure is not trivial. There are two main hypotheses for the subsurface structure of sunspots: the monolithic model and the cluster model. Local helioseismology is the only means by which we can investigate subphotospheric structure. However, as current linear…
How Can a Negative Magnetic Helicity Active Region Generate a Positive Helicity Magnetic Cloud?
Mandrini, C. H.; Schmieder, B.; Pariat, E. +2 more
The geoeffective magnetic cloud (MC) of 20 November 2003 was associated with the 18 November 2003 solar active events in previous studies. In some of these, it was estimated that the magnetic helicity carried by the MC had a positive sign, as did its solar source, active region (AR) NOAA 10501. In this article we show that the large-scale magnetic…
Modeling of EIS Spectrum Drift from Instrumental Temperatures
Fredvik, T.; Hara, H.; Watanabe, T. +2 more
An empirical model has been developed to reproduce the drift of the spectrum recorded by the EIS on Hinode using instrumental temperatures and relative motion of the spacecraft. The EIS spectrum shows an artificial drift in wavelength dimension in sync with the revolution of the spacecraft, which is caused by temperature variations inside the spec…
From the Sun to the Earth: The 13 May 2005 Coronal Mass Ejection
Jensen, E. A.; Owens, M. J.; Owen, C. J. +25 more
We report the results of a multi-instrument, multi-technique, coordinated study of the solar eruptive event of 13 May 2005. We discuss the resultant Earth-directed (halo) coronal mass ejection (CME), and the effects on the terrestrial space environment and upper Earth atmosphere. The interplanetary CME (ICME) impacted the Earth's magnetosphere and…
Ooty Interplanetary Scintillation - Remote-Sensing Observations and Analysis of Coronal Mass Ejections in the Heliosphere
Manoharan, P. K.
In this paper, I investigate the three-dimensional evolution of solar wind density and speed distributions associated with coronal mass ejections (CMEs). The primary solar wind data used in this study has been obtained from the interplanetary scintillation (IPS) measurements made at the Ooty Radio Telescope, which is capable of measuring scintilla…
Image Processing Techniques and Feature Recognition in Solar Physics
Aschwanden, Markus J.
This review presents a comprehensive and systematic overview of image-processing techniques that are used in automated feature-detection algorithms applied to solar data: i) image pre-processing procedures, ii) automated detection of spatial features, iii) automated detection and tracking of temporal features (events), and iv) post-processing task…
The Structure and Dynamics of the Upper Chromosphere and Lower Transition Region as Revealed by the Subarcsecond VAULT Observations
Nestoras, I.; Teriaca, L.; Patsourakos, S. +5 more
The Very high Angular resolution ULtraviolet Telescope (VAULT) is a sounding rocket payload built to study the crucial interface between the solar chromosphere and the corona by observing the strongest line in the solar spectrum, the Ly α line at 1216 Å. In two flights, VAULT succeeded in obtaining the first ever subarcsecond ( 0.5\hbox{$^''$} ) i…