A Comparison of Boundary Layer Heights For the Washington, D.C. Area During Late-Spring and Early-Summer 2021 between a WRF Model and Processed Ground-Based LiDAR Data

The ability to accurately model the Planetary Boundary Layer Height (PBLH) is important for the prediction of mixing in the atmosphere and thus levels of air pollution and greenhouse gases near the ground. The Baltimore Social-Environmental Collective seeks to monitor the local environment of Baltimore, MD through a variety of methods, including PBLH determined by vertical velocity variance through the usage of a Light Detection And Ranging (LiDAR) instrument. In preparation for deployment of a LiDAR in Baltimore, a nearby LiDAR in Washington, D.C. with similar detection capabilities operating from April 17 to May 7, 2021 was analyzed and compared to a Weather Research and Forecasting Model (WRF) model output which identified PBLH using Total Kinetic Energy (TKE). Specifically, a morning and an afternoon dataset were analyzed for the purpose of investigating differences between initiating and sustained surface convection processes, finding that PBLH prediction differences between the WRF and the LiDAR were statistically significant. Further consideration should be given to differences between LiDAR and WRF outputs throughout the diurnal cycle and during LiDAR-detected high backscatter events.