Unveiling Radiative Interactions in AEW-Affected Regions: Operational Insights from RTTOV Simulations

Saharan dust aerosol events significantly impact Earth's radiative balance, as their magnitude can affect atmospheric heating rates by several degrees per day. However, numerical weather prediction models often struggle to accurately represent aerosol vertical distribution, leading to forecast errors driven by biases in heating rates. The necessity for accurate forecasts in this region is underscored by the important role Saharan dust events play in the development of African Easterly Waves (AEWs) into tropical cyclones. We seek to improve forecasting in this area by analyzing how aerosol vertical distribution and related thermodynamics influence AEW development. To assess discrepancies between models and observations, we process data from several reanalyses, including the Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) and the ECMWF Reanalysis v5 (ERA5) and field data from NASA's Convective Processes Experiment - Cabo Verde (CPEX-CV). CPEX-CV sampled several AEWs over the northwest African coast, providing high resolution data on aerosol distribution and atmospheric profiles during these events. Leveraging the Community Radiative Transfer Model (CRTM) and Radiative Transfer for TOVS (RTTOV), both operationally used for simulating satellite radiances, we extend their utility to simulate radiances for diverse sensors over AEWs. This approach unveils intricate aerosol-radiation interactions across various spectral bands, enhancing our insights into atmospheric behavior. We also calculate heating rates and fluxes with the use of the 4-Stream, highly accurate Fu-Liou-Gu (FLG) radiative transfer model. Comparing several radiative transfer models allows us to assess their performance and their potential impact on satellite data assimilation systems, further enhancing forecast accuracy and enriching our grasp of radiative phenomena.