Microwave transfer model differences in remote sensing of cloud liquid water at low temperatures

Results from two popular models for the complex permittivity of liquid water were compared, as applied to radiative transfer computations in the 5-250 GHz range. Substantial differences were found in situations with cloud temperatures below 0/spl deg/C. Simulations of cloud liquid water retrievals from satellite and ground-based instruments demonstrated that uncertainties in the models at low temperatures can lead to large retrieval errors.