Confronting the Boundary Layer Data Gap: Evaluating New and Existing Methodologies of Probing the Lower Atmosphere

In recent years, much attention has turned to studying the planetary boundary layer (PBL) as advanced instruments have become more affordable. Commercial availability of scanning Doppler lidars (DLs) and the recent widespread availability of small unmanned aerial vehicles (UAS) has opened up a world of opportunity to observe and study the complex processes that occur in the PBL.

During July 14-21, 2018, the Lower Atmospheric Process Studies at Elevation - a Remotely-piloted Aircraft Team Experiment (LAPSE-RATE) field campaign took place in the San Luis Valley in south-central Colorado. During this campaign, the University of Oklahoma (OU) deployed state-of-the-art weather observing rotary wing UAS (WxUAS) platforms to study convective initiation, morning PBL transitions, and drainage flows from the surrounding mountain ranges. As part of LAPSE-RATE, OU deployed mobile UAS teams to different locations in the valley. Here we focus on data collection from a site near Moffat, CO.

At the Moffat site, in addition to the WxUAS operations, OU also deployed the Collaborative Lower Atmospheric Mobile Profiling System (CLAMPS). CLAMPS includes a Halo Photonics Streamline DL (Pearson et al. 2009), Atmospheric Emitted Radiance Interferometer (AERI, Knuteson et al. 2004a, 2004b) and a version4 Humidity And Temperature Profiler (HATPRO, Rose et al. 2005), which is a multi-channel microwave radiometer (MWR). Additionally, near-surface temperature, humidity and wind speed were measured with a Vaisala WXT-530 weather transmitter that is part of the MWR instrumentation. CLAMPS also launched radiosondes during the campaign. In addition to the CLAMPS DL, the University of Colorado operated a Leosphere Windcube Profiling DL at the Moffat site.

In total, OU flew nearly 100 UAS profiles up to 914 m, launched 20 radiosondes, recorded hundreds of Velocity Azimuth Display (VAD) scans, and retrieved hundreds of thermodynamic profiles from the AERI and MWR at the Moffat site. The colocation of these various systems provided ample opportunity to compare and contrast kinematic and thermodynamic observations from these different methodologies of boundary layer profiling, namely: WxUAS, remote sensing, and the traditional in-situ radiosonde. A detailed comparison of measurements by each system will be presented. Additionally, ideas for using each system to augment each other will be presented.