Astronomy and Astrophysics – Astrophysics
Scientific paper
Oct 1999
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1999esasp.446..201b&link_type=abstract
8th SOHO Workshop: Plasma Dynamics and Diagnostics in the Solar Transition Region and Corona. Proceedings of the Conference hel
Astronomy and Astrophysics
Astrophysics
Scientific paper
The spatial distributions of EUV line emission and relative line-of-sight velocity in the atmosphere above 22 sunspot regions are investigated. The study is based on simultaneous observations of ten EUV emission lines with the Coronal Diagnostic Spectrometer -- CDS on SOHO. Since the EUV emission lines are formed at different temperatures, we study the sunspot atmosphere from the chromosphere to the corona. We observe both a rapid variation with a characteristic time of a few to several minutes and a slow variation with a time constant of several hours to approximately one day. The sunspot plume concept is reinvented to describe the most prominent emission feature in the intensity maps in the temperature range log T approx 5.2 - 5.6. The relative line-of-sight velocity in sunspot plumes is high and directed into the Sun in the transition region. The flow is maintained by plasmas at transition region temperatures, moving from regions located at greater heights outside the sunspot and towards the sunspot. Only a few features show the signatures of a siphon flow. Comparisons of intensity and velocity maps suggest that gas at transition region temperatures occur in loops different from loops with coronal temperatures. However, we cannot exclude the presence of transition region temperatures close to the footpoints of flux tubes emitting at coronal temperatures.
Brynildsen Nils
Kjeldseth-Moe Olav
Maltby Per
No associations
LandOfFree
EUV Line Emission and Dynamics in Sunspot Regions does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with EUV Line Emission and Dynamics in Sunspot Regions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and EUV Line Emission and Dynamics in Sunspot Regions will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1084705