DOI: 10.6084/m9.figshare.22082015.v1
title: Calculation of atmospheric infrared radiation transmittance rate

description: 1. Excel is used to calculate the atmospheric transmission rate of infrared radiation. The worksheet “Earth” is the calculation of the transmission rate on the Earth and the worksheet “Hesperus” is the calculation of the transmission rate on Hesperus. Both of the results are presented in the cell “N19” of the two worksheets. The worksheet “Sheet 7” is the function diagram of the energy distribution and wavelengths of Hesperus. The worksheet “Wavelength Transmittance” is a reduction process of the transmission rates corresponding to the wavelengths with the step length of 0.1μm of the obtained image of “Radiation Transmitted by the Atmosphere”. 2. Cell “B7” in the worksheet “Earth” corresponds to the Earth’s surface temperature, the initial value of which is 288K. If the temperature is changed to 210K and 350K, that is, the value in B7 is changed to 210 and 350, the results would be 16.04% and 29.55% in N19, which is basically the same as the original 15-30%, indicating that the data is well restored according to the figures, and the calculation result of transmittance is correct. 3. There are three Plantwo of which are functions of corresponding wavelengths, and the relatick laws, onship between the two functions is a constant. Transmittance rate is a ratio, and both the numerator and denominator can present the constant outside the sum function for approximate division, so there is no difference between the results of choosing either of the two functions. 4. The restoring process of the figure of “Radiation Transmitted by the Atmosphere” is as follows: a. Grid the picture; b. Obtain the function of the number of grids corresponding to the horizontal coordinates: file:///C:\Users\ADMINI~1\AppData\Local\Temp\ksohtml12784\wps1.png, where n is the number of squares in the horizontal coordinates; c. Calculate the corresponding wavelength 10n/36.5-1 at the step length of 0.1 (the result is displayed in column D); d. Find the 1.3, 1.4, 1.5, 1.6 ......, 13.9, 14 μm in the wavelength, and check the corresponding number of horizontal coordinate squares n; e. Use the number of squares n in the “Total Absorption and Scattering” to find the corresponding atmospheric absorption rate r for that wavelength; f. Organize the data and list the 1.3 to 14 μm at the step length of 0.1 μm, and list the corresponding absorption rate r; g. Find the atmospheric transmission rate 1-r for wavelengths from 1.3 to 14 μm at the step length of 0.1 μm. Then the calculation would be easier. 5. Main radiation bands of CO2: 2.68-2.8 μm, 4.25-4.45 μm, 13-17 μm. Main radiation bands of H2O: 2.55-2.84 μm, 5.6-7.6 μm, 12-30 μm, all in the “Total Absorption and Scattering” atmospheric absorption range of infrared radiation. The calculation of transmission rate is not affected by the infrared radiation of CO2 and H2O. 6. According to the figure of “Radiation Transmitted by the Atmosphere”, the wavelength range of CO2 absorption of infrared radiation is limited. Although the atmospheric pressure of Hesperus is 96 atmospheres and the concentration of CO2 is 96.5%, CO2 has limited ability to absorb infrared radiation. The high temperatures on the surface of Venus cannot be explained only by the greenhouse effect. When calculating the atmospheric transmission rate of infrared radiation of Hesperus, the effect of carbon dioxide on the spectral absorption can be excluded by removing the 13-14 μm band from the calculation. 7. There is no independent H2CO3 in nature, which is the reason for the assumption that H2O collides with CO2 molecules without additional absorption of infrared radiation.