Comparison of DAWN, Dropsonde, and Aeolus Wind Observations during the April 2019 NASA Aeolus Cal/Val Test Flight Campaign

During April 17-30, 2019, NASA conducted an airborne field campaign based out of Palmdale, CA to demonstrate the performance of NASA’s Doppler Aerosol WiNd (DAWN) lidar and High Altitude Lidar Observatory (HALO) under a wide variety of weather and aerosol conditions and to perform initial comparisons with ESA’s ADM Aeolus Level 2 measurements. As part of this campaign, DAWN and HALO were flown on board the NASA DC-8 during five 6-10 hour long missions that included planned co-located underflights of Aeolus over the eastern Pacific Ocean.

This presentation will focus on the wind observations from both DAWN and Aeolus, as well as from Yankee Environmental Systems (YES) Dropsondes that were also part of the campaign. We will utilize the final DAWN and dropsonde data sets from the NASA DC-8 campaign and the most current Aeolus Level 2B data products.

During the approximate 45-60 minute and ~600 km long underflights of Aeolus, DAWN provided vertical profiles of the horizontal wind every 5 km from as high as 11-13 km. Up to 10 dropsondes were also deployed during these underflights. The profile comparisons between DAWN and the Dropsondes will be presented. Our main focus will be on the comparison between the wind measurements from DAWN and the Aeolus ALADIN lidar. The horizontal wind components of the DAWN profiles are used to compute a DAWN Aeolus projection of HLOS (Horizontal Line-Of-Sight) velocities. These HLOS winds are compared with the Aeolus HLOS at individual Aeolus profile locations and also integrated to match the ~85KM horizontal resolution of the Aeolus Level 2B product. These comparisons will be presented and discussed as will their impact on the design of future Cal/Val experiments.