摘要
考虑到冻融过程对于陆气相互作用的重要影响,本文将改进后的冻融参数化方案耦合到BCC_CSM2_MR模式中并进行了为期一年的模拟实验,根据土壤层的年变化将模拟时段划分为开始冻结、完全冻结、开始消融和完全消融四个阶段,分析了土壤温度、土壤温度、高原近地面风场和降水这几个气象要素。结果表明,对于浅层和深层的土壤温度,四个冻融阶段新方案的模拟都有良好的改进效果,尤其是在高原中部模拟更加准确。优化后的冻融参数化方案对土壤湿度的模拟效果改善是十分显著的,在这四个冻融时段,新方案的均方根误差和偏差在青藏高原全域都有明显的降低,主要表现在青藏高原中部地区。青藏高原上整体呈现为西风,冻结过程阶段新方案模拟结果在高原北部以及中部地区风速偏差有所减小,与对比资料更为接近;完全冻结阶段、消融过程阶段以及完全消融阶段新方案在高原北部的风速偏差减小较为明显;在冻融过程的四个阶段的降水模拟,新方案的均方根误差比原方案减小,相关系数都有提升。研究结果显示改进之后的土壤冻融参数化方案相比与原方案BCC_CSM中的模拟效果有提升,对于主要环流系统的模拟有改善。
Considering the important influence of freeze-thaw processes on land-air interactions,this paper couples an improved freeze-thaw parameterization scheme into the BCC_CSM2_MR model and conducts a one-year simulation experiment,dividing the simulation period into four stages:beginning of freezing,complete freezing,beginning of ablation and complete ablation according to the annual change of soil layer,and analyzing the soil temperature,soil temperature,near-surface wind field on the plateau and the meteorological elements of soil temperature,soil temperature,near-surface wind field and precipitation were analyzed.The results show that the new freeze-thaw scheme has good improvements for both shallow and deep soil temperatures,especially in the central part of the plateau.The improvement of the optimized freeze-thaw parameterization scheme for soil moisture is significant,and the root mean square error and bias of the new scheme are significantly reduced across the Tibetan Plateau in all four freeze-thaw periods,mainly in the central part of the plateau.The wind speed deviation in the northern and central parts of the plateau is reduced during the freezing and thawing phases,which is closer to the comparison data.The correlation coefficients have been improved.The results of the study show that the improved soil freeze-thaw parameterization scheme has a corresponding improvement over the original scheme in the BCC_CSM,and has a positive impact on the simulation of the climate and major circulation systems in China.
作者
杨凡
吕世华
张少波
徐悦
胥朋飞
游辉奇
YANG Fan;LYU Shihua;ZHANG Shaobo;XU Yue;XU Pengfei;YOU Huiqi(Sichuan Key Laboratory of Plateau Atmosphere and Environment,School of Atmospheric Sciences,Chengdu University of Information Engineering,Chengdu 610225,Sichuan,China;Key Laboratory of Land Surface Processes and Climate Change in Cold and Arid Regions,Northwest Institute of Ecological Resources and Environment,Chinese Academy of Sciences,Lanzhou 730000,Gansu,China;Lanzhou University,Lanzhou 730000,Gansu,China)
出处
《高原气象》
CSCD
北大核心
2023年第5期1093-1106,共14页
Plateau Meteorology
基金
第二次青藏高原综合科学考察研究项目(2019QZKK0103)
国家自然科学基金项目(42275080,41975007)。
关键词
青藏高原
BCC_CSM模式
土壤冻融过程
土壤温湿度
Qinghai-Xizang(Tibet)Plateau
BCC_CSM model
soil freezing and thawing processes
soil temperature and humidity
