Comment on amt-2022-235

Abstract

This study aims to generate a spatially complete planetary boundary layer height (PBLH) product over the contiguous US (CONUS) with minimal biases from observational data sets. An eXtreme Gradient Boosting (XGB) regression model was developed using selected meteorological and geographical data fields as explanatory variables to fit the PBLH values that are derived from Aircraft Meteorological DAta Reporting (AMDAR) hourly profiles at 13:00–14:00 local solar time (LST) during 2005–2019. The PBLH prediction by this work as well as PBLHs from three reanalysis datasets (ERA5, MERRA-2, and NARR) were evaluated by independent PBLH observations from spaceborne lidar (CALIPSO), airborne lidar (High Spectral Resolution Lidar, HSRL), and in-situ aircraft profiles from the DISCOVER-AQ campaigns. Compared with PBLH products from reanalyses, the model prediction from this work shows in general closer agreement with the reference observations. The reanalysis datasets show significant high biases in the west CONUS relative to the reference observations. One direct application of this dataset is that it enables sampling PBLH at the sounding locations and times of sensors aboard satellites with overpass time in the early afternoon, e.g., the A-train, Suomi-NPP, JPSS, and Sentinel 5-Precursor satellite sensors. Since both AMDAR and ERA5 are continuous at hourly resolution, future work is expected to extend the observational data-driven PBLHs to other daytime hours for the TEMPO mission.