Global ETD Search
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Showing 1 to 8 of 8 for “"Coronal Holes"”.
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The variation of coronal holes with solar cycle
Coronal holes are commonly known to be the source of the open magnetic flux and the high-speed solar wind. In EUV and X-ray emission lines, coronal holes are seen as the regions with reduced emission due to lower temperatures and electron density than the surrounding quiet sun. Observing the …
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Extreme Ultraviolet Spectroscopy of the Solar Corona
… of the solar corona, obtained by the Coronal Diagnostic Spectrometer (CDS) instrument on board the NASA/ESA Solar and Heliospheric Observatory (SOHO) are presented. The CDS instrument for the first time has provided the opportunity of observing a large number of emission lines from a …
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Effects of solar particle events on Geospace
… (i) sporadic events involving both flares and coronal mass ejections, and (ii) recurrent events driven by co-rotating interaction regions associated with fast solar wind streams from trans-equatorial coronal holes. A small proportion of these particles, of which protons are by far the most …
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Comparing Different Methods for Estimating Total Open Heliospheric Magnetic Flux
… observations) and that determined from coronal models. One explanation for the source of these discrepancies is the magnetic fields in CMEs, which have yet to magnetically disconnect from the Sun. These “closed” flux sources can be included in open flux estimates, because open and closed …
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Mode conversion and wave -particle interaction processes in the solar wind
… can occur for parameters characterizing the coronal holes. For streamer conditions, the Alfven wave couples to the slow magnetosonic mode. In the inner corona, it seems that these two possible ways of coupling do not occur simultaneously in the same structures, while beyond 5--10 R⊙ , …
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Relationship between photospheric magnetic fields and coronal activities
Coronal emission comes in two forms, a steady component where the corona is heated to million degrees and a much hotter transient component of solar flares. Both components are known to be related to the evolution of surface magnetic fields. This dissertation studies the evolution of photospheric …
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PROPERTIES AND CORRELATION OF FLARES AND CORONAL MASS EJECTIONS AND THEIR POSSIBLE RELEVANCE ON THE SOUTHERN NIGHT SKY BACKGROUND : A STATISTICAL STUDY
… statistical study of solar phenomena (flares and coronal mass ejections) and their possible effects on the Earth. The Sun, our star, can be considered a huge laboratory where we can study the interaction of a ionized gas with magnetic fields. In particular, the solar atmosphere (the outer layers …