使用加密降雪资料分析降雪量和积雪深度关系

降雪量和积雪深度的关系是降雪预报及相关科研工作中的重要参数，加密降雪资料的出现为分析这种关系提供了新的支持。利用2009—2011年冬季加密降雪资料并采用线性拟合方法，分析得出我国冬季积雪深度变化值和相应降雪量的比值大体为0.75 cm·mm-1，该比值随气温上升呈明显减小趋势，且有明显的地区差异，但未体现出显著的时间变化特征。降雪量和积雪深度的关系仍需深入分析，并需要更高质量降雪资料的支持，以便能应用到实际业务和科研工作中。

The Relationship Between Snowfall and Snow Depth Using Intensive Snowfall Observations

In China, snow disaster occurs frequently and covers a vast territory which can remarkably impact agriculture, traffic, people's life and many other aspects. The relationship between snowfall and snow depth is an important parameter for the snow forecasting and other related researches, which plays a role in snow disaster prevention and mitigation. And newly support is given with the starting of intensive snowfall observations since the winter of 2009. These new intensive snowfall observations during winters of 2009—2012 and the linear fit function of least absolute deviation method are used to analyze the relationship between snowfall and snow depth. Furthermore, the study is conducted on how it changes with conditions of different temperatures, time, regions and using other snow data.As a result, it is found that the ratio of snow depth increment to snowfall in China during winter is 0.75 cm·mm-1 in general, which is consistent with the result that using the regular winter observational rainfall and snow depth data. And it also shows that the ratio of snow depth increment to snowfall would decrease apparently with air temperature rising for the impact of temperature conditions on the state of snowing. In addition, the relationship between snowfall and snow depth presents marked difference in different region on the basis of investigating eighteen provinces in China which cover most regions that may have snow in winter. This relation is relatively stable in different temperature conditions, which also reveals that the ratio of snow depth increment to snowfall would increase slightly when temperature drops in most regions. And the relationship shows no obvious temporal variation, but it can be found that the relationship in Northwest and Northeast China is stable but fluctuant in North China and the Huanghuai Area.A preliminary analysis about the relationship between snowfall and snow depth is conducted under different conditions, its result can be used as a reference for snow depth estimation and used in weather forecasting and decision-making support. Further discussion on new data is needed to obtain more accurate and reasonable parameters in practice. Moreover, the intensive snowfall observations provide new data for snow research, but they also have many limitations which can affect the final result. Since it is a common problem that the research on snow is restricted by lacking suitable snow data, more high quality snow observations will be needed to support further analysis in the future.