Abstract:

The auroral intensity ratios at Zhongshan station on April 8, 1999 were discussed, together with the variety of penetrated electron energy, it is concluded that the ratios of I(557.7nm)/I(427.8nm) during quiet period varied from 5 to 22, as well as I(630.0nm)/I(427.8 nm) from 1 to 2.76, and the cause for the change was not the atomic oxygen concentration variety, but the penetrated electron energy variety or other mechanisms; the ratios decreased sharply during the auroral substorm, varied from 1.66 to 6.5 and 0.071 to 1 respectively, which mainly caused by the increase of penetrated electron energy. At the beginning of the auroral substorm, the ratios reached its minimum; means that the penetrated electron energy got its maximum, while auroral substorm wear off, the penetrated electron energy come back to the level of pre-substorm.

Key words: auroral substorm, intensity ratio, electron