基于Noah-MP模式的影响青藏高原冻融过程参数化方案评估

Assessment of Freeze-thaw Process Simulation in Qinghai-Tibetan Plateau by Different Parameterization Schemes based on Noah-MP Land Surface Model

针对陆面模式冻融过程模拟偏差较大问题,基于Noah-MP模式对冻融参数化方案进行比较分析,并利用观测资料对模拟试验结果进行评估。结果表明:Noah-MP模式能够较好地模拟出青藏高原冻融过程特征;冻融过程模拟对冻融参数化方案相当敏感,冻结阶段到融化阶段期间,4组试验模拟值差异显著,融化阶段之后到冻结阶段之前,4组试验模拟值相当一致;相对于过冷水参数化方案,冻土渗透率参数化方案对冻融过程期间土壤温度的模拟更为敏感,过冷水参数化方案不同会导致冻融过程期间土壤液态水含量模拟值差异显著。地表能量通量模拟对冻融参数化方案相当敏感,4组试验地表能量通量模拟值在冻结阶段、冻结稳定阶段、融化阶段均存在显著差异。

Considering the large simulation bias of the freezing-thawing process from land surface models,an comparative analysis of the freeze-thaw process parameterization schemes based on Noah-MP land surface model are carried out and the simulations of different freeze-thaw process parameterization schemes are verified by observation data.Results show that the Noah-MP land surface model can capture the characteristics of freezingthawing process.The freeze-thaw process simulation is quite sensitive to the freeze-thaw parameterization scheme.From the freezing phase to the melting phase,the simulated values of the four experimental groups are significantly different.Before the freezing phase and after the melting phase,the simulated values of the four experimental groups are quite consistent.Compared with the super cooled liquid water parameterization scheme,the frozen soil permeability parameterization scheme is more sensitive to the simulation of soil temperature during freezing-thawing period.Different super cooled liquid water parameterization schemes can cause large differences in simulated soil moisture.The simulation of surface energy flux is quite sensitive to the freeze-thaw parameterization scheme.There are significant differences in the simulation values of the surface energy flux by four tests during freezing phase,freezing stability phase and melting phase.