Turbulent Velocities and Ion Temperatures in the Solar Corona Obtained from SUMER Line Widths

摘要

Turbulent plasma velocities and ion temperatures were determined from the line widths recorded by the Solar Ultraviolet Measurements of Emitted Radiation instrument on the Solar and Heliospheric Observatory spacecraft. From the widths of the lines of five light elements (Ne, Na, Mg, Si, and S) and a heavy element (Fe), it was possible to determine the contributions of turbulent plasma motion and ion thermal motion to the line widths. The results indicated that the turbulent velocity was approximately 22 km s~-1 at 30" above the limb and decreased to less than 10 km s~-1 at 109" and 209" above the limb.