Using CALIOP to estimate cloud-field base height and its uncertainty: the Cloud Base Altitude Spatial Extrapolator (CBASE) algorithm and dataset

Attenuated backscatter profiles from the CALIOP satellite lidar are used to estimate cloud base heights of lower-troposphere liquid clouds (cloud base height below approximately 3 km). Even when clouds are thick enough to attenuate the lidar beam (optical thickness > 5), the technique provides cloud base heights by treating the cloud base height of nearby thinner clouds as representative of the surrounding cloud field. Using ground-based ceilometer data, uncertainty estimates for the cloud base height product at retrieval resolution are derived as a function of various properties of the CALIOP lidar profiles. Evaluation of the predicted cloud base heights and their predicted uncertainty using a second, statistically independent, ceilometer dataset shows that cloud base heights and uncertainties are biased by less than 10%.

CBASE provides two files for each CALIOP VFM input file: one using a 40 km window to detect the cloud field base height, and one using a 100 km window. (The input CALIOP VFM dataset is organized by the daytime/nighttime half of each orbit.) The file name pattern is

CBASE<resolution>_<date>T<time><day/night>.nc (identical to the input

CALIOP VFM file name with the exception of the product name). Files are organized into subdirectories by half-orbit start date.

Citation proposal
Johannes Mülmenstädt (Universität Leipzig) - Odran Sourdeval (Universität Leipzig) - David S. Henderson (University of Wisconsin at Madison) - Tristan S. L’Ecuyer (University of Wisconsin at Madison) - Claudia Unglaub (Universität Leipzig) - Leonore Jungandreas (Universität Leipzig) - Christoph Böhm (Universität zu Köln) - Lynn M. Russell (University of California, San Diego) - Prof. Dr. Johannes Quaas (Universität Leipzig). Using CALIOP to estimate cloud-field base height and its uncertainty: the Cloud Base Altitude Spatial Extrapolator (CBASE) algorithm and dataset. https://gdk.gdi-de.org/geonetwork/srv/api/records/de.dkrz.wdcc.iso3590248

Simple

Alternate title: Using CALIOP to estimate cloud-field base height and its uncertainty: the Cloud Base Altitude Spatial Extrapolator (CBASE) algorithm and dataset

Date ( Creation ): 2018-04-10

Identifier: None

Identifier: doi:10.1594/WDCC/CBASE / Using CALIOP to estimate cloud-field base height and its uncertainty: the Cloud Base Altitude Spatial Extrapolator (CBASE) algorithm and dataset