Search Publications
Search for Rapid Changes in the Visible-Light Corona during the 21 June 2001 Total Solar Eclipse
Keenan, F. P.; Phillips, K. J. H.; Williams, D. R. +2 more
Some 8000 images obtained with the Solar Eclipse Coronal Imaging System (SECIS) fast-frame CCD camera instrument located at Lusaka, Zambia, during the total eclipse of 21 June 2001 have been analysed to search for short-period oscillations in intensity that could be a signature of solar coronal heating mechanisms by MHD wave dissipation. Images we…
TRACE Observations of Changes in Coronal Hole Boundaries
Kahler, S.; Jibben, P.; DeLuca, E. E.
Solar coronal holes (CHs) are large regions of the corona magnetically open to interplanetary space. The nearly rigid north - south CH boundaries (CHBs) of equatorward extensions of polar CHs are maintained while the underlying photospheric fields rotate differentially, so interchange magnetic reconnection is presumed to be occurring continually a…
Modified Coronal Index of the Solar Activity
Lukáč, B.; Rybanský, M.
The original coronal index of the solar activity (CI) has been constructed on the basis of ground-based measurements of the intensities of the coronal line of 530.3 nm (Rybanský in Bull. Astron. Inst. Czechoslov., 28, 367, 1975; Rybanský et al. in J. Geophys. Res., 110, A08106, 2005). In this paper, CI is compared with the EUV measurements on the …
Measurements of Filament Height in Hα and EUV 304 Å
Xu, Yan; Jing, Ju; Wang, Haimin
In this study, we present the three-dimensional (3D) configuration of a filament observed by STEREO and the Global High Resolution H-alpha Network (GHN) in EUV 304 Å and Hα line center, respectively. This was the largest filament located close to the active region NOAA 10956 that produced a small B9.6 flare and two Coronal Mass Ejections (CMEs) on…
Periodicity of Total Solar Irradiance
Li, K. J.; Xu, J. C.; Gao, P. X. +2 more
We investigate the periodicity in the PMOD composite of the daily total solar irradiance (TSI) from 21 September 1978 to 9 June 2009. Besides the Schwabe cycle period (10.32 years), the quasi-rotation period is found to be statistically significant in TSI, whose value is about 32 days, longer than that in sunspot activity (27 days), and it intermi…
Machine Leaning-Based Investigation of the Associations between CMEs and Filaments
Ipson, S.; Colak, T.; Qahwaji, R. +1 more
In this work we study the association between eruptive filaments/prominences and coronal mass ejections (CMEs) using machine learning-based algorithms that analyse the solar data available between January 1996 and December 2001. The support vector machine (SVM) learning algorithm is used for the purpose of knowledge extraction from the association…
Automatic Determination of the Conic Coronal Mass Ejection Model Parameters
Taktakishvili, A.; Pulkkinen, A.; Oates, T.
Characterization of the three-dimensional structure of solar transients using incomplete plane of sky data is a difficult problem whose solutions have potential for societal benefit in terms of space weather applications. In this paper transients are characterized in three dimensions by means of conic coronal mass ejection (CME) approximation. A n…
Type-II Bursts in Meter and Deca - Hectometer Wavelengths and Their Relation to Flares and CMEs: II
Prakash, O.; Shanmugaraju, A.; Vršnak, Bojan +2 more
A study of the relationship between 38 type-II bursts recorded in meter and deca-hectometer (hereinafter m and DH) wavelength range and the associated flares and CMEs observed during the years 2000 - 2005 was carried out by Prakash et al. (2009). These events were divided into two classes: i) Class I, representing events where DH-type-II bursts ar…
Trans-Equatorial Loop System Arising from Coronal Hole Boundaries through Interactions between Active Regions and Coronal Holes
Masuda, Satoshi; Yokoyama, Masaki
It is not clear how trans-equatorial loop systems (TLSs) are formed, although they have been observed often with Yohkoh/SXT. We focus here on a TLS that appeared on 27 May 1998. Yokoyama and Masuda (Solar Phys.254, 285, 2009) proposed a new scenario for the formation mechanism of the TLS. In this scenario, they pointed out the importance of magnet…
Pre-Flare Flows in the Corona
van Driel-Gesztelyi, L.; Green, L. M.; Harra, L. K. +2 more
Solar flares take place in regions of strong magnetic fields and are generally accepted to be the result of a resistive instability leading to magnetic reconnection. When new flux emerges into a pre-existing active region it can act as a flare and coronal mass ejection trigger. In this study we observed active region 10955 after the emergence of s…