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…
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…
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…
A Quantitative Model of Energy Release and Heating by Time-dependent, Localized Reconnection in a Flare with Thermal Loop-top X-ray Source
Qiu, J.; Longcope, D. W.; Des Jardins, A. C. +1 more
We present a quantitative model of the magnetic energy stored and then released through magnetic reconnection for a flare on 26 February 2004. This flare, well observed by RHESSI and TRACE, shows evidence of non-thermal electrons for only a brief, early phase. Throughout the main period of energy release there is a super-hot (T≳30 MK) plasma emitt…
Reconnection of a Kinking Flux Rope Triggering the Ejection of a Microwave and Hard X-ray Source I. Observations and Interpretation
Kliem, B.; Karlický, M.
Imaging microwave observations of an eruptive, partially occulted solar flare on 18 April 2001 suggest that the global structure of the event can be described by the helical kink instability of a twisted magnetic flux rope. This model is suggested by the inverse gamma shape of the source exhibiting crossing legs of a rising flux loop and by eviden…
Outflows at the Edges of an Active Region in a Coronal Hole: A Signature of Active Region Expansion?
van Driel-Gesztelyi, L.; Baker, D.; Murray, M. J. +1 more
Outflows of plasma at the edges of active regions surrounded by quiet Sun are now a common observation with the Hinode satellite. While there is observational evidence to suggest that the outflows are originating in the magnetic field surrounding the active regions, there is no conclusive evidence that reveals how they are driven. Motivated by obs…