抄録
From the currently observed data, the absolute intensity of the solar hydrogen Lyman-alpha (H Ly-α) was estimated as 3.2×1015 photons/m2 sec at 1 A. U. and constant within ±4.2% during the period from February 24 to September 30 with some lacks of observation only. No remarkable correlations with other indices such as F10.7 and Calcium plage indices were observed. The density distribution of hydrogen atoms in the altitude range from about 800km to 3, 000km was analysed. The observed absorption profile data agreed with the simulated calculation by referring to the CIRA '72 Model Atmosphere.
