Jf. Seely et al., TURBULENT VELOCITIES AND ION TEMPERATURES IN THE SOLAR CORONA OBTAINED FROM SUMER LINE WIDTHS, The Astrophysical journal, 484(1), 1997, pp. 87-90
Turbulent plasma velocities and ion temperatures were determined from
the line widths recorded by the Solar Ultraviolet Measurements of Emit
ted Radiation instrument on the Solar and Heliospheric Observatory spa
cecraft. 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 wa
s approximately 22 km s(-1) at 30 '' above the limb and decreased to l
ess than 10 km s(-1) at 109 '' and 209 '' above the limb. At 30 '' abo
ve the limb, the ion temperatures of the hotter lines were comparable
to the electron temperatures for ionization equilibrium. The ion tempe
ratures of the cooler lines were higher than the ionization equilibriu
m temperatures; at 109 '' and 209 '' above the limb, the ion temperatu
res were at least a factor of 2.5 higher than the ionization equilibri
um temperatures.