Mass motion in the solar chromosphere

✍ Scribed by R. A. Jones; W. A. Rense

• Publisher: Springer
• Year: 1970
• Tongue: English
• Weight: 235 KB
• Volume: 15
• Category: Article
• ISSN: 0038-0938
• DOI: 10.1007/bf00151835

✦ Synopsis

A high resolution profile of the solar OI 1304.9 A line has been measured from rocket spectrograms. The profile is nearly flat-topped, showing only a slight solar reversal after instrument effects and absorption due to atomic oxygen in the earth's atmosphere have been allowed for. A theoretical analysis of this line, under the assumption of non-LTE conditions and a homogeneous, spherically symmetric chromosphere, predicts a rather deep solar reversal. The theoretical profile may be made consistent with the observed profile if mass motion is present in the chromospheric region where the line is formed. A Gaussian distribution of up and down velocities with a root mean square velocity of about 7 km/sec gives best agreement between the predicted and observed profile. This result is consistent with the conclusion made from a study of high resolution profiles of solar lines in the visible spectrum that mass vertical velocities increase with height above the photosphere.