The Impacts of Assimilating DAWN and HALO Observations on Numerical Simulations of Tropic Convections Associated with African Easterly Waves During NASA’s CPEX-AW and CPEX-CV

One of the scientific objectives of National Aeronautics and Space Administration (NASA)’s Convective Processes Experiment - Aerosols and Winds (CPEX-AW) (August and September 2021) and Convective Process Experiment - Cabo Verde (CPEX-CV) (September 2022) field campaigns is to examine the influence of observations from advanced instrumentation onboard the NASA DC-8 medium-altitude aircraft on the understanding and predictions of tropical Atlantic weather systems. This study focuses on assessing the impacts of assimilating observations from two airborne lidar systems, Doppler Aerosol WiNd lidar (DAWN) wind and High Altitude Lidar Observatory (HALO) water vapor profiles, along with the joint data assimilation (DA) of the dropsonde data, on numerical simulations of mesoscale convective systems (MCSs) associated with several African easterly wave (AEW) cases during CPEX-AW and CPEX-CV. Data are assimilated into the Weather Research and Forecasting (WRF) model using the National Centers for Environmental Prediction (NCEP) Gridpoint Statistical Interpolation (GSI)-based three dimensional ensemble-variational hybrid data assimilation (3DEnVAR) system. Comparisons of numerical results with the observations from the Airborne Precipitation Radar (APR)-3 radar and satellite-derived precipitation datasets show that assimilating DAWN winds and HALO water vapor improves short-range forecasts by simultaneously refining moisture and wind fields and suppressing spurious precipitation in clear skies. Dropsonde profiles, despite their scattered distribution, provide valuable in-cloud data that enhances the prediction of convections but introduces uncertainty. The joint data assimilation of DAWN winds, HALO water vapor, and dropsonde profiles effectively refines precipitation structures and wind fields, particularly above cloud tops, influencing convective regions from local to mesoscale. The results imply the benefit of integrated DA with dropsondes and advanced research instruments.