During June and July 1987, a major collaborative experiment (part of The First ISCCP [International Satellite Cloud Climatology Project] Regional Experiment (FIRE) took place off the coast of California to study the extensive fields of stratocumulus clouds that are a persistent feature of subtropical marine boundary layers. For the first time, measurements were made on both the regional scale and on the detailed local scale to permit the widest possible interpretation of the mean, turbulent, microphysical, radiative, and chemical characteristics of stratocumulus, together with the interactions among these quantities that am believed to he important in controlling the structure and evolution of these clouds. Multiple aircraft were used to make detailed, in situ measurements and to provide a bridge between the microscale and features seen from satellites. Ground-based remote-sensing systems on San Nicolas Island captured the time evolution of the boundary-.layer structure during the three-week dura... Abstract During June and July 1987, a major collaborative experiment (part of The First ISCCP [International Satellite Cloud Climatology Project] Regional Experiment (FIRE) took place off the coast of California to study the extensive fields of stratocumulus clouds that are a persistent feature of subtropical marine boundary layers. For the first time, measurements were made on both the regional scale and on the detailed local scale to permit the widest possible interpretation of the mean, turbulent, microphysical, radiative, and chemical characteristics of stratocumulus, together with the interactions among these quantities that am believed to he important in controlling the structure and evolution of these clouds. Multiple aircraft were used to make detailed, in situ measurements and to provide a bridge between the microscale and features seen from satellites. Ground-based remote-sensing systems on San Nicolas Island captured the time evolution of the boundary-.layer structure during the three-week dura...