BCC_AVIM陆面模式不同土壤垂直离散化方案对土壤水热输送的数值模拟  

Numerical Simulation of Soil Water and Heat Transport with Different Vertical Discretization Schemes BCC_AVIM Land Surface Model

作　　者：刘子莎 吕世华[1,2] 胥朋飞 包逸群 游辉奇 杨凡 LIU Zisha;LÜShihua;XU Pengfei;BAO Yiqun;YOU Huiqi;YANG Fan(College of Atmospheric Sciences,Chengdu University of Information Technology,Chengdu 610225,Sichuan,China;Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions,Northwest Institute of Eco-Resources and Environment,Chinese Academy of Sciences,Lanzhou 730000,Gansu,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]成都信息工程大学大气科学学院,四川成都610225 [2]中国科学院西北生态资源环境研究院寒旱区陆面过程与气候变化重点实验室,甘肃兰州730000 [3]中国科学院大学,北京100049

出　　处：《高原气象》2024年第2期303-317,共15页Plateau Meteorology

基　　金：第二次青藏高原综合科学考察研究项目(2019QZKK0103);国家自然科学基金面上项目(42275080);中国气象局地球系统数值预报中心数值预报模式研发专项(CXFZ2022M001)。

摘　　要：陆面模式中的土壤如何分层至关重要,一般情况下认为在受大气—地面界面影响较大的土壤表层应该细分,土壤越往深层,土壤层厚度的分层可以相应加大。已有研究表明:在不同天气和气候积分条件下,土壤厚度在根带以下,其对模拟结果有不同的影响。这表示根据不同的研究要求,应当改变土壤的分层方式。然而什么是陆面模式中的最优土壤分层方式仍不确定。因此本文主要利用BCC_AVIM陆面模式探究不同土壤垂直离散化方案对于土壤水热属性,表面辐射通量与感热、潜热通量模拟的敏感性,从而达到提升模式模拟效果的目的。BCC_AVIM陆面模式中原土壤分层方案为10层,将土壤各层的节点深度,土壤层厚度以及土壤各层的界面深度进行插值,由原来的10层土壤层插值到20层,在本文中称为方案一;参考模式CLM5.0中的土壤垂直离散化方案并改进到BCC_AVIM陆面模式中,原土壤层次也由10层增加到20层,为本文的方案二。将改进后的方案一和方案二与原方案结果对比分析发现:(1)方案一和方案二对土壤温度的模拟与实测数据更吻合,对于各层土壤温度的数值大小与变化趋势的模拟效果有所提升,其中方案一对浅层土壤温度的模拟效果更好。(2)在土壤湿度的模拟上,三种方案对浅层土壤湿度的模拟效果较好,对深层土壤湿度的模拟效果相对较差,其中方案一对土壤各层湿度曲线变化趋势与数值大小的模拟更加贴近实测数据。(3)方案一对土壤各层是否发生冻结或消融的时间判定更合理,更加接近实测数据。整体上,方案一的模拟效果最佳。由此,得出结论:方案一相较于原方案对土壤温、湿度的模拟效果有所改善,这表明在同样的土壤深度下,更密集更细致的土壤分层有利于提升模式对土壤水热输送的模拟能力。同时,方案一的模拟效果总体优于方案二,这也表明,在相同的土壤层次The stratification of soil in land surface models is a crucial aspect that requires careful consideration.Typically,the surface layer of soil,which is significantly influenced by the atmosphere-ground interface,should be subdivided.Furthermore,as the soil goes deeper,the thickness of the soil layers can be increased accordingly.Previous studies have demonstrated that the thickness of soil below the root zone has varying effects on simulation results under different weather and climate integration conditions.Therefore,the soil stratification mode should be adjusted based on the research requirements.However,the optimal soil stratification mode in land surface models remains uncertain.This paper aims to explore the sensitivity of different soil vertical discretization schemes to the simulation of soil hydrothermal properties,surface radiation flux,sensible heat flux,and latent heat flux using the BCC_AVIM land surface model.The original scheme of soil stratification in the BCC_AVIM land model consists of 10 layers.In this study,the node depth,soil layer thickness,and interface depth of soil layers were interpolated from the original 10 layers to 20 layers,which is referred to as scheme 1.Additionally,the vertical soil discretization scheme in CLM5.0 was used as a reference and improved for the BCC_AVIM land model.Consequently,the original soil layer was increased from 10 to 20,which is referred as scheme 2.After comparing the results of the improved schemes 1 and 2 with those of the original scheme,it is evident that:(1)The simulation results of schemes 1 and 2 are more consistent with the measured data,and the simulation accuracy of the numerical value and changing trend of soil temperature in each layer is improved.Scheme 1 performs better in simulating shallow soil temperature.(2)The three schemes have good simulation effects on shallow soil moisture,but relatively poor simulation effects on deep soil moisture.The simulation of the variation trend and numerical value of soil moisture curve in each layer in Schem

关 键 词：土壤分层 BCC_AVIM陆面过程模式 土壤水热 

分 类 号：P437[天文地球—大气科学及气象学]