Testing an Experimental Dry Snow Zdr Calibration Method on DOW (Doppler on Wheels) Data from Winter 2018

Radar meteorologists always strive for accuracy in their instrumentation to gain a thorough understanding of precipitation processes. Calibration is necessary to deduce general atmospheric microphysical processes and obtain better hydrometeor classifications. Dual-polarized radars emit electromagnetic pulses to scan the atmosphere in horizontal (H) and vertical (V) polarizations, producing two measurements of reflectivity. The difference between these signals is known as differential reflectivity (Zdr), which helps in identifying or recognizing hydrometeors. These hydrometeors have specific backscatter electromagnetic signatures, providing researchers with a reference point to calibrate radars.

This work explores an experimental approach to calibrating a meteorological radar dataset collected by a DOW (Doppler on Wheels) at Purdue University in March 2018. The field work was conducted at a Purdue field research site located 8.6 km from Purdue’s main campus in West Lafayette. Two Zdr calibration methods were tested: a conventional vertical scanning method and the dry snow method. The research aims to evaluate the suitability of the dry snow calibration method for X-band radar in winter precipitation. The results of the summer dataset are reported elsewhere in this conference. The preliminary findings indicate that the dry snow method technique shows promise, but has significant limitations.