Cloud top height derived from airborne measurements with the WALES lidar during the EUREC4A field campaign|气象学数据集|激光雷达数据集

This dataset contains cloud top data derived from airborne measurements with the WALES lidar during the EUREC4A field campaign . Lidar raw data at a temporal resolution of 5 Hz were used, which corresponds to 40 m horizontal spacing. The vertical resolution of the backscatter data is 7.5 m . The cloud flag is inferred from a step of the lidar backscatter ratio at 532 nm to values bigger than 10, while searching from the aircraft downwards. To further facilitate the discrimination of optically thin clouds and opaque ones the atmospheric optical depth between the cloud top and the sub-cloud layer is included in the data set. Values above 2 to 3, depending on the background light situation, are only rough estimates, but indicate the presence of on optically thick, opaque cloud. The data also includes the altitude of the cloud top as height above the EGM96 geoid with a precision of about 10 m and an accuracy of about the same magnitude. Further included is an estimation of the altitude of the top of the boundary layer above sea level. This is inferred from the maximum correlation of the lidar backscatter ratio profile at 532 nm with a step function. This quantity is experimental and should be interpreted with care, especially in the presence of residual layers or strong horizontal wind shear which may cause multi-layer structures. In the case of a cloud, no PBL-top is given.