Use of Multi-Resolution Imager Data to Account for Partially Cloud-Filled Pixels

Partially cloud-filled pixels are a significant problem for satellite remote sensing of cloud properties. Optical depths and effective particle sizes are often too small or too large, respectively, when derived from radiances that are assumed to be overcast but contain radiation from both clear and cloud areas within the satellite imager field of view. This has been demonstrated most recently by Dong et al. (2002), which compared surface and satellite retrievals over the Atmospheric Radiation Measurement (ARM) Program’s Southern Great Plains (SGP) Central Facility (CF). For example, the breakup of a solid cloud deck caused a rapid divergence of the two retrieved cloud droplet sizes in one of their case studies. This effect is important because it biases the statistics of the cloud properties being generated for ARM over all surface sites. Minimization of the effect is necessary to increase the accuracy of the ARM satellite cloud products.