E3C10 : What does the 304A solar parameter measure?
A
The ratio of X-ray flux to radio flux, correlated to sunspot number
B
UV emissions at 304 angstroms, correlated to the solar flux index
C
The solar wind velocity at an angle of 304 degrees from the solar equator, correlated to geomagnetic storms
D
The solar emission at 304 GHz, correlated to X-ray flare levels
Correct Answer: UV emissions at 304 angstroms, correlated to the solar flux index