Retrieval and Parameterization of Melting Layer Attenuation at Ku‐ and Ka‐Bands Using Long‐Term Multi‐Frequency Radar Observations

Abstract The melting layer (ML) in stratiform precipitation can have attenuation effects on microwave signals, introducing major uncertainties in remote sensing and telecommunications. In this study, we derived parameterizations for ML attenuation at the Ku‐ and Ka‐bands, which are frequencies widely used in ground‐based and spaceborne meteorological radars. To achieve this, a Doppler‐spectra‐based dual‐frequency differential approach was applied to a unique, long‐term multi‐frequency radar data set. Our results suggest that total ML attenuation strongly depends on the ML thickness, while the specific ML attenuation aligns well with previous case studies and simulations. Furthermore, we quantified the impact of riming snow on ML attenuation, and found that the Ka‐band specific ML attenuation for rimed snow is nearly half that of unrimed snow in light rainfall, whereas this distinction becomes obscured as the rain rate increases. Based on the Ku‐ and Ka‐band ML parameterizations (derived as functions of rain rate and reflectivity, respectively), we extended these parameterizations to the W‐band to facilitate broader applications across diverse radar missions. By presenting the first long‐term observational analysis of Ku‐ and Ka‐band ML attenuation, this study facilitates the accurate quantification of ML attenuation, serving as a unique reference for ground‐based and spaceborne radar observations.