The atmospheric boundary layer (ABL) has strong diurnal variability, but routine radiosonde launches at 00:00 and 12:00 UTC cannot fully resolve its daily evolution. This study develops and evaluates a 13-year (2007–2019) hourly ABL profile dataset using Aircraft Meteorological Data Relay (AMDAR) observations from 42 selected European airports, and applies it to characterize airport-scale diurnal, seasonal, and regional variations in ABL structure. AMDAR-derived temperature and wind profiles were validated against collocated radiosonde observations by season, pressure layer, and airport–radiosonde distance. Errors decrease for shorter separation distances and lower-tropospheric layers. For separations 850 hPa, spring, summer, autumn, and winter RMSEs are 0.9/1.0/1.4/1.2 K for temperature, 1.7/2.0/1.9/1.9 m/s for zonal wind, and 1.4/1.6/1.9/1.6 m/s for meridional wind. Hourly AMDAR profiles reveal distinct diurnal ABL evolution at airport scale. Seasonal ABL height (ABLH) composites are mainly 250–900 m, with available nighttime and early-morning values of about 300–450 m and spring–summer afternoon maxima of 800–900 m at far-inland airports. Coastal airports show weaker daytime growth, mostly below 600–650 m. These results demonstrate AMDAR’s value as a supplementary profile dataset for characterizing European airport-scale ABL structure and diurnal variability.
Liu et al. (Fri,) studied this question.