Search Publications
Evolution of Coronal Mass Ejections in the Inner Heliosphere: A Study Using White-Light and Scintillation Images
Manoharan, P. K.
Knowledge of the radial evolution of the coronal mass ejection (CME) is important for the understanding of its arrival at the near-Earth space and of its interaction with the disturbed/ambient solar wind in the course of its travel to 1 AU and further. In this paper, the radial evolution of 30 large CMEs (angular width > 150∘, i.e., …
The Depiction of Coronal Structure in White-Light Images
Morgan, Huw; Habbal, Shadia Rifai; Woo, Richard
The very steep decrease in density with heliocentric distance makes imaging of coronal density structures out to a few solar radii challenging. The radial gradient in brightness can be reduced using numerous image processing techniques, thus quantitative data are manipulated to provide qualitative images. We introduce a new normalizing-radial-grad…
Using the Evolution of Coronal Dimming Regions to Probe the Global Magnetic Field Topology
Mandrini, C. H.; Dasso, S.; Harra, L. K. +4 more
We demonstrate that study of the evolving magnetic nature of coronal dimming regions can be used to probe the large-scale magnetic structure involved in the eruption of a coronal mass ejection (CME). We analyse the intensity evolution of coronal dimming regions using 195 Å data from the Extreme ultraviolet Imaging Telescope (EIT) on board the Sola…
Correlation Between Solar Flare Productivity and Photospheric Magnetic Field Properties. 1. Maximum Horizontal Gradient, Length of Neutral Line, Number of Singular Points
Wang, Huaning; Cui, Yanmei; Li, Rong +2 more
From a large number of SOHO/MDI longitudinal magnetograms, three physical measures including the maximum horizontal gradient, the length of the neutral line, and the number of singular points are computed. These measures are used to describe photospheric magnetic field properties including nonpotentiality and complexity, which is believed to be cl…
Properties of Flares-Generated Seismic Waves on the Sun
Kosovichev, A. G.
The helioseismic waves excited by solar flares ("sunquakes") are observed as circular, expanding waves on the Sun's surface. The first sunquake was observed for a flare on July 9, 1996, by the Solar and Heliospheric Observatory (SOHO) space mission. This paper presents results of new observations and a detailed qualitative analysis of the basic pr…
The Deceleration of an Interplanetary Transient from the Sun to 5 Au
Tappin, S. J.
A CME which was first seen in LASCO is tracked through SMEI and on out to Ulysses. These measurements allow us to determine the deceleration and compare different models of the deceleration process. It is found that both a simple "snow plough" model and an aerodynamic drag model predict a much more rapid deceleration in the lower solar wind than i…
Companion Event and Precursor of the X17 Flare on 28 October 2003
Mandrini, C. H.; Schmieder, B.; Pariat, E. +3 more
A major two-ribbon X17 flare occurred on 28 October 2003, starting at 11:01 UT in active region NOAA 10486. This flare was accompanied by the eruption of a filament and by one of the fastest halo coronal mass ejections registered during the October-November 2003 strong activity period. We focus on the analysis of magnetic field (SOHO/MDI), chromos…
Analysis of Magnetic Shear in An X17 Solar Flare on October 28, 2003
Golub, L.; Su, Y. N.; Gros, M. +1 more
An X17 class (GOES soft X-ray) two-ribbon solar flare on October 28, 2003 is analyzed in order to determine the relationship between the timing of the impulsive phase of the flare and the magnetic shear change in the flaring region. EUV observations made by the Transition Region and Coronal Explorer (TRACE) show a clear decrease in the shear of th…
Calibration of the Soho/Lasco C3 White Light Coronagraph
Llebaria, A.; Plunkett, S. P.; Lamy, P. +16 more
We present a detailed review of the calibration of the LASCO C3 coronagraph on the SOHO satellite. Most of the calibration has been in place since early in the mission and has been utilized to varying degrees as required by specific analysis efforts. However, using observational data from the nearly decade-long database of LASCO images, we have re…
A Multi-Wavelength Study of the Compact M1 Flare on October 22, 2002
Mason, H. E.; Schmieder, B.; Berlicki, A. +1 more
In this paper we present a further study of the Ml class flare observed on October 22, 2002. We focus on the SOHO Coronal Diagnostic Spectrometer (CDS) spectral observations performed during a multi-wavelength campaign with TRACE and ground-based instruments (VTT, THEMIS). Strong blue-shifts are observed in the CDS coronal lines in flare kernels d…