Fig. 1. Flowchart of atmospheric radiative transfer model construction

Fig. 2. Flowchart of random forest regression model construction

Fig. 3. Tropospheric height of eastern China region in different months

Fig. 4. Classification of temperature and pressure over eastern China in different months

Fig. 5. Temperature patterns of different categories in the eastern China. (a) January; (b) April; (c) July; (d) October

Fig. 6. Pressure profiles of different ategories in the eastern China region in January

Fig. 7. Regional mean pressure profiles for representative months. (a) 1–20 km; (b) 7–13 km

Fig. 8. Classification results of water vapor profiles in the eastern China region for different months

Fig. 9. Water vapor patterns of different categories in the eastern China. (a) January; (b) April; (c) July; (d) October

Fig. 10. Classification results of ozone profiles in the eastern China region for different months

Fig. 11. Ozone patterns of different categories in the eastern China. (a) January; (b) April; (c) July; (d) October

Fig. 12. Total volume fraction of CH₄ in the eastern China region for different months

Fig. 13. Methane patterns in the eastern China region for representative months

Fig. 14. CO₂ volume fraction in the eastern China region for different months

Fig. 15. Carbon dioxide patterns in the eastern China region

Fig. 16. Comparison of radiation transfer simulation results from 1976 US standard atmosphere model and self-built atmospheric model with HIRAS measured spectra in July

Fig. 17. Deviation between simulated spectra and measured spectra in July

Fig. 18. Comparison of radiation transfer simulation results from 1976 US standard atmosphere model and self-built atmospheric model with HIRAS measured spectra in January

Fig. 19. Deviation between simulated spectra and measured spectra in January