Calculation of the Solar Radiation Field in the General Circulation Model of the Earth’s Lower and Middle Atmosphere

• Published in: Mathematical models and computer simulations Vol. 15; no. 2; pp. 189 - 201
• Main Author: Fedotova, E. A.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.04.2023; Springer Nature B.V
• Subjects: Altitude; Atmospheric circulation; Earth surface; Frequency ranges; Gas composition; General circulation models; Mathematical Modeling and Industrial Mathematics; Mathematics; Mathematics and Statistics; Middle atmosphere; Optical thickness; Parameterization; Radiation; Simulation and Modeling; Solar radiation; Very high frequencies; intrinsic radiation in the atmosphere; solar radiation in the atmosphere; general circulation model of the Earth’s atmosphere
• ISSN: 2070-0482; 2070-0490
• DOI: 10.1134/S2070048223020047

The results of testing two radiation blocks used for the cost-effective calculation of radiation transfer in the general circulation model of the lower and middle atmosphere of the Earth are presented. The first block is designed to calculate the field of intrinsic radiation in the frequency range from 10 to 3000 cm −1 , and the second block is designed to calculate the field of solar radiation in the frequency range from 2000 to 50 000 cm −1 . Each of these blocks uses its own parameterization of the optical parameters of the air in the altitude range from the Earth’s surface to 90 km. When constructing these parameterizations, the change in the gas composition of the atmosphere with altitude was taken into account. For the numerical solution of the radiation transfer equation, the method of discrete ordinates is used. The results of calculations performed using the radiation block of the model are compared with the results of line-by-line (LBL) calculations of the solar radiation field in the lower and middle atmosphere of the Earth, performed with a very high frequency resolution. It is shown that the model block provides accurate calculations both in the absence of clouds and in the presence of cloud layers with a large optical thickness.