Comparison of the Intensity of the Nighttime Scattered Atmospheric Radiation in the Lyman-Alpha Line from OGO-4 Satellite Measurements and Calculations

• Published in: Geomagnetism and Aeronomy 2020-07, Vol.60 (4), p.489-494
• Main Authors: Pavlov, A. V., Pavlova, N. M.
• Format: Article
• Language: English
• Subjects: Alpha particles; Alpha radiation; Alpha rays; Atmospheric radiation; Atomic properties; Density; Earth and Environmental Science; Earth Sciences; Empirical models; Geophysics/Geodesy; Hydrogen; Lyman-alpha radiation; Mathematical models; Night; Oxygen; Radiation absorption; Satellite instruments; Satellite-borne instruments; Satellites; Solar activity; Solar radiation
• ISSN: 0016-7932; 1555-645X; 0016-7940
• DOI: 10.1134/S001679322004012X

A theoretical model has been developed for the calculation of the intensity and flux of nighttime Lyman-alpha solar radiation at altitudes of the atmosphere that takes into account the multiple scatterings of this radiation by atmospheric atomic hydrogen. At heights of more than two Earth radii, the number density of atomic hydrogen is calculated by an empirical model based on the agreement of the results of calculations of the Lyman-alpha radiation intensity with the results of measurements of this intensity by TWINS 1 and 2 satellites instruments. At lower heights, it is calculated according to the NRLMSISE-00 empirical model. The temperature of neutral atmospheric components and the O 2 number density are taken according to the NRLMSISE-00 model, and the absorption of Lyman-alpha radiation by molecular oxygen is taken into account. The results of measurements of the integral intensity of the Lyman-alpha radiation intensity by the wavelength instruments of the OGO-4 satellite at an height of 650 km are compared at night on January 31, 1968, at high solar activity with the results of model calculations of this intensity. It is shown that the 1.2-fold decrease in [H] in the NRLMSISE-00 model at heights of less than two Earth radii allows satisfactory agreement between the calculated and measured intensities of the radiation in question.