中文摘要：

用从 2 月跨越时期到 2009 年 12 月的观察数据并且在 Qinghai 省在 Suli 车站记录了，陆地表面模型 CLM3.0 被采用模仿结冰并且融化土壤。结果比观察土壤温度和最终的融化日期在融化的时期期间是比观察日期早的的显示模仿的土壤温度高。在结冰时期期间，模仿的土壤温度比观察土壤温度并且深土壤的最终的结冰比观察的早的低。总的来说，结冰的模拟比融化的好，并且浅层的模拟比更深的层的好。在原来的 CLM3.0，土壤温度什么时候超过 0，被假定冻结的土壤开始融化 ? 慣汬摥琠? 桴 ? 慢吗？

英文摘要：

Using observational data spanning the period from February to December 2009 and recorded at the Suli station in Qinghai Province,the land-surface model CLM3.0 was employed to simulate the freezing and melting of soil.The results indicate that the simulated soil temperature is higher than the observed soil temperature and the ultimate thawing date is earlier than the observed date during the melting period.During the freezing period,the simulated soil temperature is lower than the observed soil temperature and the ultimate freezing of the deep soil is earlier than that observed.Overall,the simulation of freezing is better than that of melting,and the simulation of a shallow layer is better than that of a deeper layer.In the original CLM3.0,it is assumed that frozen soil begins to melt when the soil temperature exceeds 0C,which is inconsistent with observations.The critical freeze–thaw temperature was calculated according to thermodynamics equations and the freeze-thaw condition was modified.In this work,the melting rate for frozen soil was reduced using the modified scheme,and the simulated soil temperature was lowered. Meanwhile,the refreezing of soil during the melting season was well simulated and more closely matched observations.Additionally,it was found that the rates of melting and freezing differ,with the former being slower than the latter,but refreezing during the melting season is rather quick.