This study investigates the characteristics of cold clouds and snowfall in both the Yeongdong coastal and mountainous regions under different meteorological conditions based on the integration of numerical modeling and three-hourly rawinsonde observations with snow crystal photographs for a snowfall event that occurred on 29–30 January 2016. We found that rimed particles predominantly observed turned into dendrite particles in the latter period of the episode when the 850 hPa temperature decreased at the coastal site, whereas the snow crystal habits at the mountainous site were largely needle or rimed needle. Rawinsonde soundings showed a well-defined, two-layered cloud structure along with distinctive wind-directional shear, and an inversion in the equivalent potential temperature above the low-level cloud layer. The first experiment with a decrease in lower-layer temperature showed that the low-level cloud thickness was reduced to less than 1.5 km, and the accumulated precipitation was decreased by 87% compared with the control experiment. The difference in precipitation amount between the single-layered experiment and control experiment (two-layered) was not so significant to attribute it to the effect of the seeder-feeder mechanism. The precipitation in the last experiment by weakening wind-directional shear was increased by 1.4 times greater than the control experiment specifically at the coastal site, with graupel particles accounting for the highest proportion (∼62%). The current results would improve snowfall forecasts in complicated geographical environments such as Yeongdong in terms of snow crystal habit as well as snowfall amount in both time and space domains.

中文翻译：

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韩国永东地区降雪特征对气象条件的敏感性

本研究基于数值模拟和 1 月 29 日至 30 日发生的降雪事件的 3 小时原始探测与雪晶照片相结合，研究了不同气象条件下永东沿海和山区的冷云和降雪特征。 2016. 我们发现在沿海站点850 hPa温度下降时，主要观察到的边缘颗粒在事件后期转变为枝晶颗粒，而山区站点的雪晶习性主要是针状或边缘针状。Rawinsonde 探测显示出清晰的两层云结构以及独特的风向切变，以及低层云层上方等效位温的反转。第一次降低低层温度实验表明，低层云层厚度减少到1.5公里以下，累积降水量比对照实验减少了87%。单层实验与对照实验（两层）的降水量差异不显着，不能将其归因于播种-喂料机制的影响。通过减弱风向切变，上次实验中的降水比对照实验增加了 1.4 倍，特别是在沿海站点，其中霰粒占最高比例（~62%）。