Surface-based remote sensing of the observed and the Adiabatic liquid water content of stratocumulus clouds

A laser ceilometer, an acoustic sounder, and a microwave radiometer were used to estimate cloud thickness and the adiabatic and integrated liquid water content of shallow stratocumulus clouds continuously for three days using two‐minute averages. Although the observed liquid water path was close to the theoretical adiabatic value for most of the three days, there was one four‐hour period when the liquid water content dropped to about 50% of the adiabatic value. Hourly‐averaged values for a 19‐day period of intensive observations show that the cloud water content was generally close to the adiabatic value. Occasionally there were clouds greater than 300 m in depth in which the water content was clearly less than adiabatic.