Polar lights,the interaction of solar wind particles with atmospheric molecules

The aurora is caused by the excitation processes realized when the solar wind particles-electrons and protons collide with atmospheric nitrogen and oxygen molecules. Solar wind particles reach the Earth's magnetosphere where they are captured by the magnetic field and enter the atmosphere at the poles. The work mainly deals with the excitation processes of the molecular band spectrum of the nitrogen molecular ion. In particular, the excitation processes of the molecular band spectrum of the nitrogen ion N_2^+ in the visible region of radiation are discussed. The paper presents the results related to the measurement of the excitation cross-section of the band spectrum of the first negative system B^2 ∑_u^+→X^2 ∑_g^+) upon collision of electrons and hydrogen H^+ ions with N_2 molecules.