The XPIA lidar scanning strategies were designed to extract quantitative information about different aspects of the atmospheric boundary layer velocity field (Mann et al.
Approximately 345 h of stare scans throughout XPIA were targeted at the tower sonics; all such data over the period of the deployment are included here.
To enable more rapid vertical profiling than possible with coordinated stares, XPIA tested an approach in which each lidar executed a "vertical slice" or RHI scan, with the intersection line at the lidar supersite for heights between 60 and 200 m (0300-0400 UTC 21 April).
During the XPIA field deployment, several experiments were conducted to coordinate simultaneous multi-Doppler lidar and dual-Doppler Ka-band radar measurements and to compare the respective retrievals.
For the XPIA geometry, considering wind speeds between 5 and 10 m [s.
Despite the 144 h of LCB scanning conducted during XPIA, only 20 min of overlap existed between LCB and dual-Doppler Ka-band radar (DDR) retrievals.
To quantify the uncertainty of routine assessments of atmospheric stability, M WR measurements of temperature structure were compared to the six levels of temperature measurements on the BAO tower as well as to temperature profiles from the soundings launched during XPIA.
To facilitate access to all the data collected during XPIA, the DOE Atmosphere to Electrons (A2e) initiative has established a data access portal (https://a2e.
Beyond the instrumentation evaluations discussed here, XPIA documented several meteorological case studies ideal for challenging and improving numerical models at both the mesoscale and large-eddy simulation scale.
Other time periods in the XPIA dataset contain phenomena of interest, such as low-level jets, density flows, and clear-air vortices.
Designed to assess instrumentation capabilities for quantifying the complex flows within wind farms, XPIA employed numerous scanning lidars, scanning radars, profiling lidars, and radiometers, as well as radiosondes, radar wind profilers, and a heavily instrumented 300-m meteorological tower.
Volumetric data from scanning instruments can provide a powerful tool for evaluating simulations, and XPIA developed scanning strategies to compare volumes from the rapidly scanning radars with a large checkerboard (LCB) volume collected from the lidars.