Search Publications
Dynamics of a Quiescent Solar Prominence Observed with the SUMER/SOHO Instrument
Bocchialini, K.; Rovira, M.; Costa, A. +3 more
We present the results obtained from analyzing SUMER/SOHO observational data of a quiescent solar prominence. The studied prominence is made of complex structures. From the 1-hr data set, we derive characteristic frequencies in terms of intensity and velocity oscillations, as measured in 4 transition-region lines. The presence of different types o…
Erupting Magnetic Structures observed with SOHO/LASCO
Simnett, G. M.; Lyons, M. A.
We report observations, from March 1999 to December 1999, of slow-moving, low-mass (≲1014 g) erupting structures. The 20 events seen in this period appear with a double or multiple loop structure. Their speeds range from approximately 10 to 60 km s−1. There are no significant associated flares or radio signatures. Although th…
Common characteristics of CMEs and BLOBs: a new view of their possible origin
Eselevich, M. V.; Eselevich, V. G.
An analysis of the LASCO/SOHO data has shown that blobs are similar, in their basic characteristics, to CMEs, having a relatively small size and relatively low velocities. The formation of blobs and CMEs is usually accompanied by the process where a separate ray (or rays) of the streamer belt becomes occupied by additional anti-sunward traveling p…
Multi-scale temporal features of the 14 July 2000 meter- wavelength dynamic radio spectrum compared with TRACE data
Grechnev, V. V.; Chertok, I. M.; Nightingale, R. W. +5 more
The 14 July 2000 (`Bastille Day') eruptive and geoeffective flare event was observed by the digital IZMIRAN radio spectrograph in the frequency range of 25-270 MHz. This instrument allowed the analysis of various features of the dynamic radio spectrum and their comparison with other observational data, in particular with development of a spectacul…
SWRI/LASP Sounding Rocket Inter-Calibration With The Eit Instrument On Board SOHO
Slater, David C.; Hassler, Donald M.; Auchère, Frédéric +1 more
Two successful sounding rocket flights were launched on 15 May 1997 and 2 November 1998 with an objective of providing inter-calibration with several of the instruments on board SOHO and TRACE. We will discuss here the results of the inter-calibration between the SwRI/LASP rocket imaging instruments and the Extreme-ultraviolet Imaging Telescope (E…
Solar Large-Scale Emitting Chains: Evidence of Reality and Some Properties
Chertok, I. M.
A phenomenon of large-scale solar activity - relatively weak extended emitting chains with a characteristic length comparable with the solar disk radius or even diameter - were detected recently on the modified heliograms in the microwave (Nobeyama radioheliograph), soft X-ray (Yohkoh/SXT), EUV (SOHO/EIT, TRACE), and some other ranges. In this pap…
Energetic Particle Fluxes during the Bastille Day Solar Eruption
Mäkelä, Pertti; Torsti, Jarmo
We report on our observations of solar energetic particle fluxes of p, He, C, O, Ne, Mg, Si, and Fe ions measured by the Energetic and Relativistic Nucleon and Electron (ERNE) experiment associated with the Bastille Day solar flare and coronal mass ejection (CME) on 14 July 2000. We observed two clear maxima of the Fe/O ratio at the energies 8.5-1…
Solar Si XI Line Ratios Observed by the Normal Incidence Spectrometer on SOHO CDS
Brooks, D. H.; Thompson, W. T.; Lang, J. +3 more
New measurements of line intensity ratios in the Be-like ion Si xi are presented for observations of the quiet Sun, active regions, coronal holes and above-limb regions obtained using the Coronal Diagnostic Spectrometer on the Solar and Heliospheric Observatory. A model ion, constructed using the best available atomic data, is used to predict the …
Analysis of a UV Event in a Polar Coronal Hole
Patsourakos, Spiros; Vial, Jean-Claude
We present observations of a UV event which occurred in a polar coronal hole. They were obtained by SUMER on SOHO in several chromospheric and transition region spectral lines. Its birth site was about 50 arc sec inside the limb and in a network lane showing a net outflow before its initiation. The event had an extension of about 5 arc sec along t…
Low-Order p Modes From Virgo Irradiance Data
Finsterle, W.; Fröhlich, C.
Several candidates for low-order p modes (n ≤ 5) and possibly g modes were found by applying mode-detection techniques such as multivariate spectral regression analysis and time-frequency analysis to the VIRGO full-disc solar irradiance data. Three out of the candidates for low-order p modes could be confirmed by significant peaks in the un-treate…