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A New Forecasting Index for Solar Wind Velocity Based on EIT 284 Å Observations
Luo, Bingxian; Zhong, Qiuzhen; Liu, Siqing +1 more
Various solar wind forecasting methods have been developed during the past decade, such as the Wang - Sheeley model and the Hakamada - Akasofu - Fry Version 2 (HAFv2) model. Also, considerable correlation has been found between the solar wind speed v and the coronal hole (CH) area AM on the visible side of the Sun, showing quantitative …
Observations of Low-Latitude Coronal Plumes
Wang, Y. -M.; Muglach, K.
Using Fe IX/X 17.1 nm observations from the Extreme-Ultraviolet Imaging Telescope (EIT) on the Solar and Heliospheric Observatory (SOHO), we have identified many coronal plumes inside low-latitude coronal holes as they transited the solar limb during the late declining phase of cycle 23. These diffuse, linear features appear to be completely analo…
Short-Period Fluctuations in Coronal Mass Ejection Activity during Solar Cycle 23
Lara, Alejandro; Borgazzi, Andrea; Mendes, Odim, Jr. +2 more
We have constructed a time series of the number of coronal mass ejections (CMEs) observed by SOHO/LASCO during solar cycle 23. Using spectral analysis techniques (the maximum entropy method and wavelet analysis) we found short-period (< one year) semiperiodic activity. Among others, we found interesting periodicities at 193, 36, 28, and 25 days…
A Study of Surges: II. On the Relationship between Chromospheric Surges and Coronal Mass Ejections
Liu, Yu
Liu et al. (Astrophys. J.628, 1056, 2005a) described one surge - coronal mass ejection (CME) event showing a close relationship between solar chromospheric surge ejection and CME that had not been noted before. In this work, large Hα surges (>72 Mm, or 100 arcsec) are studied. Eight of these were associated with CMEs. According to their distinc…
A Low-Frequency (30 - 110 MHz) Antenna System for Observations of Polarized Radio Emission from the Solar Corona
Ramesh, R.; Kathiravan, C.; Barve, Indrajit V. +2 more
An interferometer antenna system to observe polarized radio emission from the solar corona at different frequencies in the range 30 - 110 MHz has been commissioned recently by the Indian Institute of Astrophysics at the Gauribidanur Radio Observatory (latitude 13°36'12''N and longitude 77°27'07''E), abou…
Modeling of Solar Wind in the Coronal Funnel with Mass and Energy Supplied at 5 Mm
Tu, C. -Y.; Marsch, E.; He, J. -S.
The origin of the solar wind is a long-standing issue in both observational and theoretical studies. To understand how and where in the solar atmosphere the mass and energy of the solar wind are supplied is very important. Previous observation suggests a scenario in which the fast solar wind originates at heights above 5 Mm in the magnetically ope…
Segmentation of Loops from Coronal EUV Images
Feng, L.; Inhester, B.; Wiegelmann, T.
We present a procedure to extract bright loop features from solar EUV images. In terms of image intensities, these features are elongated ridge-like intensity maxima. To discriminate the maxima, we need information about the spatial derivatives of the image intensity. Commonly, the derivative estimates are strongly affected by image noise. We ther…
Seismic Emissions from a Highly Impulsive M6.7 Solar Flare
Moradi, H.; Donea, A. -C.; Martínez-Oliveros, J. C.
On 10 March 2001 the active region NOAA 9368 produced an unusually impulsive solar flare in close proximity to the solar limb. This flare has previously been studied in great detail, with observations classifying it as a type 1 white-light flare with a very hard spectrum in hard X-rays. The flare was also associated with a type II radio burst and …
Automated Prediction of CMEs Using Machine Learning of CME - Flare Associations
Ipson, S.; Colak, T.; Qahwaji, R. +1 more
Machine-learning algorithms are applied to explore the relation between significant flares and their associated CMEs. The NGDC flares catalogue and the SOHO/LASCO CME catalogue are processed to associate X and M-class flares with CMEs based on timing information. Automated systems are created to process and associate years of flare and CME data, w…
Can We Constrain Solar Interior Physics by Studying the Gravity-Mode Asymptotic Signature?
García, R. A.; Mathur, S.; Ballot, J.
Gravity modes are the best probes to infer the properties of the solar radiative zone, which represents 98% of the Sun's total mass. It is usually assumed that high-frequency g modes give information about the structure of the solar interior whereas low-frequency g modes are more sensitive to the solar dynamics (the internal rotation). In this wor…