Polarsondes for Ground-Based and Atmospheric Profiling Applications

The goal of this work is to focus on a new sounding sensor called polarsonde to measure the particle phase and shape using the linear depolarization ratio. The sensor is being developed by University of Adelaide, Australia, and modified by DMT (Droplet Measurements Technologies) Inc., Boulder, Colorado, for operational applications. The polarsonde interfaced with an IMET radiosonde receiving station for the profiling of atmosphere during snow storms and clouds occurred over the Goose Bay Upper Air Site, Labrador, Canada was part of the SAAWSO (Satellite Applications for Arctic Weather and SAR (Search And Rescue) Operations) project. During SAAWSO project, various new sensors for ground-based and profiling applications were tested during February of 2014 winter. The two versions of polarsonde were used during SAAWSO project: 1) polarsonde-G (ground version) and 2) polarsonde-R (radiosonde version). The polarsonde comprises a pulsed LED with polarized output and two photodetectors which have polarizing filters in front of them. One of the polarizers has its transmission axis perpendicular to that of the LED, and the other parallel. The relative amount of photocurrent from each detector is determined by the shape of cloud particle that scatter emitted light back toward the photodetectors. The polarsonde-G is for particle polarization information on the ground and mounted at 3 m height on a trailer pole. The polarsonde-R integrated with a radiosonde was attached underneath a balloon and used for 4 profiles over 4 days. In this work, ground based microphysical observations as well as observations from lidar, ceilometer, microwave radiometer, and radiosonde are used for validations of polarsonde-G and -R measurements, and challenges related to this new profiling system are emphasized.