Radiative Examination of Developing African Easterly Waves and Saharan Dust Interactions: Comparative Insights from Reanalysis and NASA Airborne Observations

Abstract

Abstract. This study thoroughly examines the impact of aerosols on atmospheric heating rates over the North Atlantic Ocean, with a specific focus on developing African Easterly Waves (AEWs). It utilizes data from the NASA DC-8 aircraft, dropsonde profiles, lidar observations, and satellite-based precipitation data obtained during NASA’s CPEX-CV field campaign, as well as MERRA-2 and CAMS reanalyses. Using a four-stream radiative transfer model, the research focuses specifically on days characterized by Saharan dust coinciding with AEWs and tropical storm development and also contrasts its findings with a notable dust-only event in June 2020. The findings reveal notable differences in shortwave (SW) and longwave/infrared (LW/IR) heating rates, underscoring the persistent challenges in accurately representing aerosol effects in the atmosphere, even after assimilating observational data. These discrepancies persisted on days with both background and high dust concentrations, emphasizing the challenges in accurately representing aerosol radiative effects in models and highlighting the urgent need for improved aerosol representation in reanalysis datasets.