Evaluating the Polarimetric Radio Occultation Technique Using NEXRAD Weather Radars

Abstract

Currently, it remains a challenge to effectively monitor areas experiencing intense precipitation and the associated atmospheric conditions on a global scale. This challenge arises due to the limitations on both active and passive remote sensing methods. Apart from the lack of observations in remote areas, the quality of some observations deteriorates when heavy precipitation is present, making it difficult to obtain highly accurate measurements of the thermodynamic parameters driving these weather events. However, there is a promising solution in the form of the Global Navigation Satellite System (GNSS) Polarimetric Radio Occultation (PRO) technique. This approach provides a way to assess the large-scale bulk-hydrometeor characteristics of regions with heavy precipitation and the meteorological conditions associated with them. PRO offers vertical profiles of atmospheric variables, including temperature, pressure, water vapor pressure, and information about hydrometeors, all in a single fine-vertical resolution observation. To continue validating the PRO technique, we make use of polarimetric weather data from Next Generation Weather Radars (NEXRAD), focusing on comparing specific differential phase shift (Kdp) structures to PRO observable differential phase shift (ΔΦ). We have seen that PAZ and NEXRAD exhibit a good agreement on the vertical structure of the observable ΔΦ and that their combination could be useful for enhancing our understanding of the microphysics underlying heavy precipitation events.

Keywords

• Global Navigation Satellite Systems (GNSS)
• Polarimetric Radio Occultations (PRO)
• Next Generation Weather Radars (NEXRAD)