A cloud climatology of the Southern Great Plains ARM CART

Cloud amount statistics from three different sources were processed and com pared. Surface observations from a National Centers for Environmental Predi ction dataset were used. The data (Edited Cloud Report; ECR) consist of syn optic weather reports that have been edited to facilitate cloud analysis. T wo stations near the Southern Great Plains (SGP) Cloud and Radiation Test B ed (CART) in north-central Oklahoma (Oklahoma City, Oklahoma and Wichita, K ansas) were selected. The ECR data span a 10-yr period from December 1981 t o November 1991. The International Satellite Cloud Climatology Project (ISC CP) provided cloud amounts over the SGP CART for an g-yr period (1983-91). Cloud amounts were also obtained from Micro Pulse Lidar (MPL) and Belfort C eilometer (BLC) cloud-base height measurements made at the SGP CART over a 1-yr period. The annual and diurnal cycles of cloud amount as a function of cloud height and type were analyzed. The three datasets closely agree for total cloud amount. Good agreement was found in the ECR and MPL-BLC monthly low cloud amounts. With,th the exception of summer and midday in other sea sons, the ISCCP low cloud amount estimates ate generally 5%-10% less than t he others. The ECR high cloud amount estimates are typically 10%-15% greate r than those obtained from either the ISCCP or MPL-BLC datasets. The observ ed diurnal variations of altocumulus support the authors' model results of radiatively induced circulations.