Snow particle size distribution (PSD) information is important in understanding the microphysics and quantitative precipitation estimation over complex terrain. Measurement and interpretation of the snow PSDs is a topic of active research. This study investigates snow PSDs during 3 year of observations from Parsivel² disdrometers and precipitation imaging packages (PIP) at five different sites in the PyeongChang region of South Korea. Variabilities in the values of the density of snow ($\rho$), snowfall rate ($S$), and ice water content ($IWC$) are studied. To further understand the characteristics of snow PSD at different density and snowfall rate, the snow particle size distribution measurements are divided into six classes based on the density values of snowfall and five classes based on snowfall rates. The mean shape factors ($D_m$, $lo{g}_{10}{N}_w$, and $\mu$) of normalized gamma distribution are also derived based on different density and snowfall rate classes. The $D_m$ decreases and $lo{g}_{10}{N}_w$ and μ increase as the density increases. The $D_m$ and $lo{g}_{10}{N}_w$ increase and μ decreases with the increase of snowfall rate. The power-law relationship between $\rho$ and $D_m$ is obtained and the relationship between $S$ and $IWC$ is also derived.

中文翻译：

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韩国平昌地区积雪粒径分布特征

雪粒大小分布（PSD）信息对于理解复杂地形上的微物理学和定量降水估算非常重要。雪PSD的测量和解释是积极研究的主题。这项研究调查了在韩国平昌地区五个不同地点的Parsivel ²测速计和降水成像软件包（PIP）进行3年观测期间的雪PSD 。雪密度值的变化（$\rho$），降雪率（$\mathrm{小号}$）和冰水含量（$\mathrm{一世}\mathrm{w\; ^}C$）进行研究。为了进一步了解不同密度和降雪率下雪PSD的特性，根据降雪的密度值将雪的粒径分布测量分为六类，并根据降雪率分为五类。平均形状因子（$d_{米}$， $升ØG_{10}{ñ}_w$和 $\mu$还基于不同的密度和降雪率类别推导了γ归一化的伽玛分布。的$d_{米}$ 减少和 $升ØG_{10}{ñ}_w$和μ随着密度的增加而增加。的$d_{米}$ 和 $升ØG_{10}{ñ}_w$随着降雪率的增加，μ增加而μ减小。之间的幂律关系$\rho$ 和 $d_{米}$ 获得和之间的关系 $\mathrm{小号}$ 和 $\mathrm{一世}\mathrm{w\; ^}C$ 也得出。