Analysis of Characteristics of Precipitation Particle on Heavy Rain-Snow Process in Dabie Mountain in Anhui Province

The cloud and precipitation mechanism could be studied by investigating the characteristics of precipitation particle.Characteristic analysis of particle concentration,falling velocity as well as their spectrum distribution in different precipitation patterns was made according to 2540 sharing data during 26-28 January 2008 observed by OTT Parsivel laser precipitation particle measuring system installed at the top unobstructed platform of the building of Anhui Qianshan Meterological Station near Dabie Mountains.The results have shown:(1) During the snowstorm,the average number concentration is the largest in the case of sleet,up to 589 per min,and the least is in rain,only 255 per min.(2) The concentrations of snow and freezing rain exhibit a form of double peak,other forms of precipitation are in single peak.(3) Different precipitation particle sizes mainly lay between 0.125-1.00 mm,with the widest spectrum being snow, and the narrowest being drizzle.The mean spectrum of each form of precipitation has a single peak with different peak values.(4) The maximum falling velocity of each form of precipitation is primarily concentrated within 1.0-4.8 m·s~(-1),98.68%in drizzle,98.46%in drizzle with rain,97.72%in rain,94.79% in sleet,93.69%in freezing rain,while 85.83%in snow.(5) The widest mean velocity spectra are in rain and sleet,and the maximum velocity could be up to 9.6 m·s~(-1).The narrowest velocity spectrum is in drizzle,with its maximum being 5.6 m·s~(-1) Other velocity spectra appear generally similar.The mean velocity spectrum of each form of precipitaion has a single peak,but their peak positions are different each other.These results provide reference for the investigation on mechanism of icy rain and snow weather, and also provide theoretic basis for weather modification.