ESTIMATION OF FREEZING LEVEL USING POLARIMETRIC RADAR TO DETERMINE THE TYPE OF PRECIPITATION IN WINTER SEASON

Abstract

 The type of precipitation on the ground in winter season is the most important information to estimate the risk of snow damages. As a commonly used method to determine type of precipitation, there is a method using the temperature as a threshold value. But the accuracy becomes poor near 0°C. Therefore, we consider to use the snowflakes melting model, and use polarimetric radar for making initial value, freezing level and particles diameter. In this study, we develop the method to estimate freezing level using polarimetric radar. In winter precipitation cases, it is confirmed that our developed method can estimate freezing level in more cases and improve the accuracy than previous studies method. And we applied developed method to snowflakes melting model as initial value and compered with ground observation. As a result, it was found that by using liquid water content calculated by the melting model, it is possible to make a more detailed determination of the precipitation type than using only the temperature.