Abstract Observations with the High Resolution Telescope and Spectrograph (HRTS) of the C IV lines at 1550 Å above sunspots reveal the co-existence of several distinct high velocity gas components within the instrument resolution element of 1 × 1 arc second. A further investigation of the HRTS material demonstrates that such multiple gas velocities are not restricted to the temperature region around 105 K, where the C IV lines are formed, but that the gas flows with essentially unchanged speed through all temperature layers from 2.5 × 105 K to 104 K. Furthermore the phenomenon is not restricted to sunspots, but occurs also in other solar regions, often most easily distinguished in active regions. We describe the characteristics of the velocity fields, analyze the mass fluxes and discuss the requirements they place on the resolving power of future space instruments.
Multiple flow velocities in the transition region
Advances in Space Research ; 11 , 5 ; 251-254
1991-01-01
4 pages
Article (Journal)
Electronic Resource
English
Multiple flow velocities in the transition region
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