The influence of temperature on the simulated high resolution spectra of enhanced SCIATRAN model in near infrared band

To analyze the effect of temperature gradients between latitudes on high resolution spectra for global CO2 observation in near infrared band, based on the enhanced SCIATRAN radiative transfer model, the spectra of the O2-A band and CO2 1.6 μm band in different temperature-latitude distribution are simulated and analyzed. For O2-A band, the intensity of simulated spectra increases with latitude in the 757-760 nm band and 766-772 nm band and decreases with the increase of latitude in 760-766 nm band. For CO2 band (1570-1618 nm), the intensity of simulated spectra is one magnitude lower than that in O2-A band and the variations are relatively complex with temperature-latitude. The spectral radiation intensity is highly depending on the temperature-latitude distributions and is sensitive to the variations of temperature-latitude, i.e., that the latitudinal distributions of temperature influence the final computation for simulated high resolution spectra and further affect the accuracy of the retrieved concentration of CO2, especially in mid-latitudes and high latitudes. This study provides a theoretical guide for developing an operational retrieval algorithm of global CO2 hyperspectral observation in near infrared.