陆面模式中土壤湿度影响蒸散参数化方案的评估

Evaluation of the Parameterization of Soil Moisture Influence on Evapotranspiration in Land Surface Models

本文将四个常见陆面模式CLM3.5(Community Land Model Version 3.5)、Noah_LSM(The Noah Land Surface Model)、VIC(Variable Infiltration Capacity)以及SSiB(The Simplified Simple Biosphere Model)中土壤湿度影响蒸散的参数化方案进行简化,并利用实验观测资料对不同参数化方案进行评估,探究不同陆面模式对土壤湿度与蒸散关系的模拟差异,从而为提高模式的模拟能力提供依据。结果表明,(1)CLM与SSiB中计算土壤湿度影响裸土蒸发的参数化方案较Noah_LSM和VIC更接近真实的物理过程,同时CLM与SSiB模式中土壤湿度对蒸发的影响程度较Noah_LSM和VIC大;而对于下垫面有植被条件下的蒸散而言,CLM中包含了植被光合作用、呼吸作用等生物物理学过程,与实际情况更为接近,并且CLM与SSiB中土壤湿度对植被蒸散的影响程度大于VIC,Noah_LSM最低;(2)根据干旱区、半干旱区、半湿润区以及湿润区各站点的分析可知,CLM、SSiB与Noah_LSM中土壤湿度影响蒸散的参数化方案的拟合效果较VIC好,同时在部分站点CLM与SSiB的参数化方案稍优于Noah_LSM。区域之间比较说明,四个模式对干旱半干旱区的模拟效果明显较半湿润区和湿润区好。

In this paper, the parameterization schemes of soil moisture influence on evapotranspiration in four widely used land surface models, i.e. CLM3.5（Community Land Model Version 3.5）, Noah_LSM（The Noah Land Surface Model）, VIC（Variable Infiltration Capacity） and SSi B（The Simplified Simple Biosphere Model）, are simplified. Experimental observation data are used to evaluate the performance of these parameterization schemes and assess the simulation ability of the models on the relationship between soil moisture and evapotranspiration for the purpose to provide theoretical bases for improving the simulation ability of models. Results indicate that the parameterization schemes of soil moisture influence on bare soil evaporation in CLM and SSi B are more consistent with the real physical processes than those in Noah_LSM and VIC, and the impacts of soil moisture on bare soil evaporation in CLM and SSi B are greater than those in Noah_LSM and VIC. For vegetation evapotranspiration, the parameterization scheme of soil moisture influence on evapotranspiration in CLM is more realistic than those in the other three models, and the impacts of soil moisture on vegetation evapotranspiration in CLM and SSi B are greater than that in VIC and the impact in Noah_LSM is the weakest. Observation data in arid region, semi-arid region, semi-humid region and humid region are analyzed respectively. Results show that the parameterization schemes of soil moisture influence on evapotranspiration in CLM, SSi B and Noah_LSM are better than that that in VIC, and the parameterization schemes in CLM and SSi B are better than that in Noah_LSM at several stations. In addition, the parameterization schemes in all the four models perform better in arid and semi-arid regions than in semi-humid and humid regions.