A constrained algorithm for retrieval of stratocumulus cloud properties using solar radiation, microwave radiometer, and millimeter cloud radar data

Nonprecipitating liquid phase clouds of the planetary boundary layer are important components of the Earth's energy budget. Modem remote sensors are able to probe these clouds with increasing precision and detail, and extensive boundary layer cloud data sets are being generated at multiple sites around the world. In this paper we integrate several recent cloud property retrieval algorithms targeted at boundary layer stratocumulus clouds into a single framework that returns the vertical profile of microphysical properties. The new algorithm guarantees consistency among the radar reflectivity profile, the microwave radiometer-derived liquid water path, and the surface solar flux transmission ratio. We demonstrate a 0.9 mum root-mean-square difference and 0.89 correlation coefficient when results from the new approach are compared to aircraft-observed volume mean cloud droplet radii. An additional stratocumulus case study observed at an Atmospheric Radiation Measurement site is briefly described.