Estimation of stratocumulus-topped boundary layer depth using sea surface and remotely sensed cloud-top temperatures

Abstract

The depth of the marine atmospheric boundary layer (MABL) is an important parameter for both scientific and operational meteorological applications. The depth of the marine boundary layer has a significant influence on the atmospheric dynamics in the coastal zone. Knowledge of the depth of stratocumulus-topped boundary layers (STELs) will enable coastal operations to more accurately anticipate weather, and electromagnetic propagation conditions. This study develops a satellite remote sensing technique for determining the height of MABLs topped with stratocumulus clouds. Validation of the technique using coastal rawinsonde dataset from the Monterey Area Ship Track (MAST) experiment revealed that an assumption of 41% cloud with a moist lapse rate equal to -7.0 deg C/km had the best overall fit to the data. However, for shallow boundary layers with depths below 400m the most accurate assumption was 75% cloud with a moist lapse rate equal to -6.5 deg C/km. The application of this technique to sounding data returned an overall BL depth accuracy of 50m while the satellite application returned an overall accuracy of 65m. A sensitivity analysis of both surface and cloud-top temperature revealed that a 1/2 deg C change in either temperature resulted in an error of 60-70m in boundary layer depth