Comparison of Four Instruments for Measuring Solid Precipitation Below the Freezing Point Condition

A comparative observation of solid precipitation was carried out at conditions below freezing point during the winter of 2005-2006 by using four instruments, including non-collecting measurement instruments. Based on a comparison with the measured increment of snow water equivalent data, data corrected for the catch ratio from a Japanese standard precipitation gauge (RT-4), measured data from a non-collecting sensor using a laser beam (PWD11) and a totalizer using a load sensor (T-200B) accurately determined the amount of solid precipitation. The measured T-200B data fluctuated during the period of non-precipitation. Positive results of consecutive time were obtained from the measured PWD11 and T-200B data. Data collected in this study from a non-collecting sensor using microwaves (R2S) were unstable or underestimated the amount of precipitation.