Microphysical Characteristics of Winter Storms Using Ground-based Polarimetric Radars and Aircraft Observations

摘要

The consistency of the various data sets collected during the AIRS field program points out the richness of this experiment in terms of the remote sensing of winter precipitation. The information contained in Z_(DR) and φDP fields provided considerable insight into the nature of the particles and their spatial extent. In the example shown here, the presence of a layer of secondary ice production has potential impact on the depletion of supercooled drops from the layer below. This illustrates the challenge to existing radar-based precipitation type algorithms to account for the spatial/temporal variability of microphysical properties both in the horizontal and vertical. Issues such as sharp gradients of reflectivity, weak reflectivity and the importance of processes in the lowest levels of the atmosphere where ground clutter can be a problem need to be adequately addressed. During the AIRS field program, data were collected on 23 precipitation events. Future work will assess the value of radar polarization diversity in an operational setting during winter storms with a focus on the identification of heavy snowfall, freezing precipitation (both rain and drizzle) and hazardous in-cloud icing conditions.