Hail Identification Algorithm for DPR Onboard the GPM Satellite

Extreme precipitation, such as hail, has raised interest due to its high impact on human activities. In the new version of Global Precipitation Measurement (GPM) dual-frequency spaceborne weather radar (DPR) algorithm (version 7), a hail product is developed to identify hail along a vertical profile. The novelty of this algorithm offers the potential for retrieving a uniform and homogeneous hail dataset on the global scale from spaceborne radar sensor. The algorithm is built upon the precipitation-type index (PTI) developed for the GPM DPR. PTI has been shown to be effective in separating various precipitation types such as snow, graupel, and hail profiles. The capabilities of this algorithm to capture hail are validated by analyzing hail observations from various space and ground sources. These include ground validation radar Next Generation Radar (NEXRAD), GPM Microwave Imager (GMI)-based hail identification, and multiple scattering effect from Trigger module of DPR level-2 algorithm. The global-scale analysis demonstrates the good performance of the hail algorithm in identifying the worldwide high-frequency hail regions and seasonal transitions.