土壤冻融过程中的水热参数化方案研究进展  

Advances in the Study of Thermal and Hydraulic Parameterizations for Soil Freeze-Thaw Process

作　　者：侯雅 李伟平[2] 左金清[3] HOU Ya;LI Weiping;ZUO Jinqing(State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,China Meteorological Administration,Beijing 100081,China;Earth System Modeling and Prediction Centre,China Meteorological Administration,Beijing 100081,China;Key Laboratory for Climate Prediction Studies,National Climate Centre,China Meteorological Administration,Beijing 100081,China)

机构地区：[1]中国气象科学研究院灾害天气国家重点实验室,北京100081 [2]中国气象局地球系统数值预报中心,北京100081 [3]中国气象局气候预测研究重点开放实验室/国家气候中心,北京100081

出　　处：《高原气象》2025年第1期1-15,共15页Plateau Meteorology

基　　金：国家重点研发计划项目(2023YFC3007503,2017YFA0604304);中国气象局气候预测创新团队项目(CMA2023ZD03)。

摘　　要：冻土是陆地冰冻圈的重要组成部分,其冻融循环变化能够影响土壤结构、土壤水热传输以及土壤生物化学等过程,并通过陆-气相互作用影响局地甚至全球天气气候。因此,研究土壤冻融过程对冻土区人类生产生活和了解区域外天气气候变化具有重要的科学意义。本文回顾了土壤中的砾石、有机质对土壤冻融过程的影响及物理机制,总结了土壤冻融过程中水热参数化的相关研究成果,包括土壤导热率和水力学参数的计算、水热耦合方案以及冻融锋面计算方案等。相对于普通的矿物质土粒而言,砾石具有高导热率和低热容,有机质具有低导热率和高热容,他们对热量在土壤中的传输及土壤温度垂直分布有不同的影响。另外,砾石和有机质的存在改变了土壤孔隙度、土壤基质毛细作用与吸附作用,进而影响水分在土壤中的传输过程和垂直分布。已有研究表明:(1)当前大部分数值模式中土壤导热率采用Johansen方案及其派生方案进行计算,其中Balland-Arp方案考虑了砾石和有机质对土壤导热率的影响,该方案更好地刻画了土壤冻融过程中土壤导热率变化的连续性;综合考虑热-水-变形相互作用的导热率参数化方案可以较好地刻画土壤冻融过程中的水热耦合和土体冻胀的作用,对相变过程中土壤导热率变化特征的模拟更符合实际观测。(2)过冷水参数化方案刻画了土壤液态水在0℃以下存在的事实;相变温度方案描述了土壤相变温度低于0℃且不固定的事实;导水阻抗方案考虑了土壤冻结对土壤水分下渗的阻抗作用,改善了对冻土区水文过程的模拟效果。(3)土壤冻融过程伴随着水分的相变和能量的转化,水热耦合方案的发展能够较好地刻画土壤中热力-水文过程的协同变化特征,细化了对冻融过程中水分和能量相互作用的复杂物理机制的描述。(4)等温框架的数值模式通过模拟�Frozen soil is the essential component of terrestrial cryosphere.Soil freeze-thaw process(SFT)affects soil structure,soil hydrothermal transfer,and biogeochemical processes,thereby influencing local and global weather and climate through land-atmosphere interaction.Therefore,it is of importance to explore SFT for human activities in frozen soil regions and for studying weather and climate change for local and remote regions.This paper reviews the effects and physical mechanisms of gravel and soil organic matter(SOM)on soil thermal and hydrological parameters and SFT,and summaries achievements in parameterizations of SFT,with focuses on soil thermal conductivity,hydraulic parameters,water-heat coupled parameterization,and freezethaw fronts.Gravel(SOM)has higher(lower)thermal conductivity and lower(higher)heat capacity,and thus they have different effects on the soil heat transfer and vertical distribution of soil temperature.Additionally,the existences of gravel and SOM change soil porosity,matrix capillary and adsorption,thereby affecting the transfer and vertical distribution of soil water content.Previous studies show that:(1)the Johansen scheme and its derivatives are widely incorporated into land models to calculate soil thermal conductivity.In consideration of the effect of gravel and SOM on soil thermal conductivity,the Balland-Arp scheme,a derivative of the Johansen scheme,better describes soil thermal conductivity during SFT.The thermal-hydro-deformation interaction thermal conductivity scheme comprehensively describes the water-heat coupling and frost heave impacts,resulting in more accurate simulation of characteristics of soil thermal conductivity in the drastic phase transition.(2)Supercooled water parameterization scheme can depict the existence of liquid water below 0°C in soil.Variable freezing threshold parameterization depicts that water phase transition to ice happens below 0°C.Taking account of the impedance of soil ice to liquid water infiltration improves model performance in simulating the

关 键 词：土壤冻融过程 参数化方案 土壤导热率 土壤水文参数 冻融锋 水热耦合 

分 类 号：P404[天文地球—大气科学及气象学]