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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…
Search for Microflaring Activity in the Magnetic Network
Falchi, A.; Cauzzi, G.; Falciani, R.
We analyze the temporal behavior of network bright points (NBPs) searching for low-atmosphere signatures of flares occurring on the magnetic network. We make use of a set of data acquired during coordinated observations between ground-based observatories (NSO/Sacramento Peak) and the MDI instrument on board SOHO. Light curves in chromospheric spec…
Characteristics of a type II solar radio burst on 22 March 1998
Shanmugaraju, A.; Umapathy, S.; Balasubramanian, V.
A solar radio type II burst (which was seen as two patches of emission, one during 07:00-07:13 UT and other one during 07:20-07:35 UT) was observed on 22 March 1998 using the Madurai radio spectrograph. A broad range of data (from Culgoora and Hiraiso spectrographs, white-light data from SOHO/LASCO and X-ray data from Yohkoh and GOES satellites) w…
Inhomogeneity in the solar core
Gough, D. O.
In recent years, normal-mode helioseismology has shown that the spherically averaged sound-speed distribution throughout the solar interior is in remarkable agreement with suitable standard solar models. This implies that any deviation of the theoretical models from the Sun has only a very small influence on the oscillation frequency spectrum (exc…