Atmospheric Transmission Spectra in the Infra-Red at High and Low Resolution

Spectrum of atmospheric vertical transmission across thermal infra-red wavelengths (for an example atmospheric state). Transmission is the fraction of the radiance leaving the Earth's surface that reaches the top of the atmosphere. Many gases contribute to the absorption features (non-perfect transmission), and the effects of the main ones are shown cumulatively here using different colours. Blue: transmission accounting for water vapour (H2O) only, showing the line features (spikes) and continuum. Pink: transmission accounting for H2O and carbon dioxide (CO2). Green: H2O, CO2 and ozone (O3). Cyan: H2O, CO2, O3 and nitrous oxide (N2O). Grey: H2O, CO2, O3, N2O and methane (CH4). Yellow: H2O, CO2, O3, N2O, CH4 and nitrogen (N2). (a) Upper panel is presented at high spectral resolution within the main atmospheric window. Absorption is by H2O, CO2, and O3. (b) Lower panel is presented a low spectral resolution, and shows the broad thermal atmospheric windows (3.5 to 4.1 mm , 8.2 to 9 mm, and 10 to 12.5 mm). Vertical lines indicate the location of the range of the upper panel.