Research on radiative transfer characteristics of oil spills in coupled atmosphere–ocean system using the CAORTS model

Accurate understanding of the radiative characteristics of oil spills and the effect of atmospheric radiative propagation within the coupled atmosphere–ocean system is crucial for enhancing the accuracy of their remote sensing identification. In this paper, a coupled atmosphere–ocean system radiative transfer simulation model (CAORTS) is developed, and its accuracy and reliability are verified by comparing it with the results from the MODTRAN software and other scholarly research. The model is employed to examine the reflectance characteristics of oil spills and to assess the effects of atmospheric propagation. The results indicate that the surface reflectance (R_sfc) and the top of atmosphere reflectance (R_TOA) of emulsified oil spills are significantly affected by the atmospheric propagation. The scattering caused by atmospheric aerosols and clouds introduces diffuse incidence, resulting in higher R_sfc than the actual reflectance of the emulsified spill at low incident angles, whereas the reverse scenario occurs at high incident angles. The R_TOA of the atmosphere is influenced by a variety of factors. Atmospheric gas absorption, in conjunction with aerosol and cloud scattering, reduces the R_TOA. In contrast, the direct reflection and scattering of solar radiation by aerosols and clouds lead to an enhancement of R_TOA. An analysis of atmospheric correction for R_TOA is conducted using this model. The analysis shows the effectiveness of the radiative transfer model developed in this study in correcting the atmospheric effects. The findings are significant for examining the radiative propagation effect of various atmospheric and oceanic components, and enhancing quantitative remote sensing identification of marine oil spills.