TY JOUR TI Effect of the NO concentration on the ratio I₅₅₇.₇/I₄₂₇.₈ in auroras KW nitric oxide KW 557.7 nm and 427.8 nm emissions KW intensity ratio KW aurora KW modeling KW electron precipitation JO Solnechno-Zemnaya Fizika AU Ivanov, V.E. AU Dashkevich, Z.V. PY 2024 IS 10 PB INFRA-M Academic Publishing LLC.