METEOROLOGICAL CHARACTERISTICS OF A HEAVY SNOWFALL EVENT BASED ON MULTI-DOPPLER RADARS OVER SAPPORO AREA

Abstract

 It is possible to discuss three dimensional fields of atmosphere by using multi-doppler and variational principle. This study adopted two X-band multi-parametric radars and analyzed meteorological fields for a heavy snowfall event which was associated with a small low pressure system over Ishikari Bay. The variational method used in this study has been developed for airborne-type and adjusted to apply for ground-based radars. Results showed that horizontal wind convergence was detected in lower troposphere over a coastal zone of Ishikari Bay which is northwesterly located from Sapporo area. In addition, stronger reflectivity propagates to southeasterly direction including Sapporo area. Obtained wind vectors in the variational method was validated with those in a numerical model and radiosonde observation, respectively.