Multiple downflow velocities above sunspotss
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Supersonic transition zone downflow appears to be commonly occurring above sunspots. The downflow has been observed in 29 emission lines in the ultra-violet spectrum with the High Resolution Telescope and Spectrograph (HRTS) on two rocket flights and on 5 consecutive days during the Spacelab-2 mission. Spectra from the second rocket flight, contain the most extreme example of downflow, showing speeds up to 180 km s−1 and extending over 60 are sec along the slit. The observations demonstrate the existence of several different distinctive flow speeds within the 1 arc sec resolution element throughout the temperature range 7000–240 000 K.
KeywordsHigh Resolution Transition Zone Emission Line Flow Speed Resolution Element
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