ERA5 CLOUD BASE HEIGHT VALIDATION BASED ON MARINE LIDAR

The Cloud Base Height (CBH) is a key parameter that influences climate conditions and aviation safety. Additionally, in some cases, CBH can serve as an estimate of the thickness of the planetary boundary layer. Accurate assessment of CBH is important for meteorological forecasts and the evaluation of the atmospheric climate characteristics and their trends. This article presents the results of the validation of the Cloud Base Height (CBH) obtained from the ERA5 reanalysis using high-precision data collected from the shipborne lidar of the research vessel “Akademik Fedorov” during the 69th Russian Antarctic Expedition (RAE-69). For validation, the model estimates of CBH from the ERA5 reanalysis, provided at a spatial resolution of 0.25°×0.25° and a temporal resolution of 1 hour, are compared with the lidar data, which were obtained in monitoring measurements with a 1-minute interval. The analysis results showed that the ERA5 data exhibit systematic deviations from the instrumental measurements, which is confirmed by the sample evaluation of the mean bias and standard deviation of the errors in the model estimates of CBH. A similar conclusion can be drawn by examining the quantile-quantile diagram of CBH values in the ERA5 model estimates and the lidar measurement data. The error map analysis of ERA5 reveals an uneven spatial distribution and a significant dependence on the latitude of observations.The results of this research can be used for further research in the fields of meteorology and climatology, as well as for improving the methods of modeling the Cloud Base Height.