Two years of continuous Doppler lidar observations at Cabo Verde: Validation of Aeolus wind products

In the framework of the Joint Aeolus Tropical Atlantic Campaign (JATAC), a scanning HALO photonics Doppler lidar has been deployed at Mindelo, Cabo Verde, since 2021 to study atmospheric dynamics and to validate the wind products of the Aeolus mission. The ground-based Doppler lidar was usually operating in stare mode (vertical profiling), but each 15 minutes a plan position indicator (PPI) scan was performed to derive vertical profiles of the horizontal wind speed and direction. Due to the vicinity of the measurement site in the middle of the Atlantic Ocean west of arid Africa, aerosol from the ground up to 4-7 km can be observed year-round, allowing to retrieve wind profiles up to this altitude. We used these profiles to validate the Aeolus L2B wind products from the direct overpasses at the site each Friday from June 2021 to April 2023 (end of Aeolus operations). The evaluation of the operational Aeolus wind products (Baseline 12 to 16) in the time period from July 2021 to April 2023 revealed a systematic error of 0.09 (0.88) m/s and a random error of 7 (3.5) m/s for the Rayleigh (Mie) products.