The extreme ultraviolet day airglow

Abstract

Satellite observations of the earth's extreme ultraviolet day airglow between 350 and 1400 Å are described. The atomic spectrum shows lines of O II (538–539, 555, 601, 617, 673, 718, 834), He I 584, O I (989, 1152, 1304, 1356), N II (916, 1085), N I (1134, 1200), and H I (1025, 1216, and possibly 973). Previously unobserved weak O II lines (515, 482, 470, 442) are observed below 530 Å. The Lyman‐Birge‐Hopfield (LBH) and Birge‐Hopfield (BH) bands of N 2 between 900–1100 Å are the dominant molecular lines. Large scale high latitude and equatorial enhancements and hemispheric asymmetries are evident in the near zenith O II 834, O I 989 and N II 1085‐Å line intensities.