利用1979-2018年中国区域地面气象要素驱动数据集(0.1°×0.1°)作为大气强迫资料,驱动CLM5.0(Community Land Model version 5.0)模拟了青藏高原地区1979-2018年的土壤温湿度变化.将土壤冻融过程划分为冻结期和非冻结期,通过两个阶段的CLM5.0模拟与站点观测资料、同化资料(GLDAS-Noah)、卫星遥感资料(MODIS 土壤温度资料和ESA CCI-COMBINED 土壤湿度资料)的对比验证,探讨CLM5.0模拟土壤温湿度在青藏高原的适用性.结果表明:(1)CLM5.0可较准确地描述站点土壤温湿度的动态变化,CLM5.0模拟的土壤温湿度与观测资料具有一致的变化特征且数值上较为接近.CLM5.0模拟的准确性高于GLDAS-Noah.CLM5.0对站点土壤温度的描述更为准确.(2)CLM5.0能够较准确地描述高原冻融过程中的土壤温湿度特征,CLM5.0模拟土壤温湿度与MODIS和ESACCI-COMBINED遥感资料在高原总体呈显著正相关,相关系数大多在0.9以上.CLM5.0对土壤温度的模拟能力相对较好,对非冻结期土壤湿度的模拟能力优于冻结期.CLM5.0整体高估了土壤温度,平均偏差大多在0～4 ℃之间.土壤湿度的平均偏差大多在-0.1～0.1m3·m-3之间,非冻结期的平均偏差相对较小.(3)CLM5.0模拟、GLDAS-Noah、MODIS和ESACCI-COMBINED遥感资料的土壤温湿度均具有相似的空间分布,其中土壤温度空间分布特征相似度更高.CLM5.0具有较高的空间分辨率和更为精细的土壤分层,对土壤温湿度细节的刻画更为完善.(4)CLM5.0模拟资料在高原整体呈增温变干趋势,MO-DIS和ESA CCI-COMBINED遥感资料整体呈增温增湿趋势.CLM5.0模拟的土壤温度变化趋势相对准确,土壤湿度的变化趋势则存在较大偏差.
Simulation and Evaluation of Soil Temperature and Moisture during Freeze-thaw Process in Xizang Plateau by CLM5.0
The China Meteorological Forcing Dataset(0.1°×0.1°)from 1979-2018 was used as atmospheric forcing data to drive CLM5.0(Community Land Model version 5.0)to simulate soil temperature and moisture changes in the Qinghai-Xizang Plateau region from 1979 to 2018.Divide the soil freeze-thaw process into two stages:freezing period and thawing period.By comparing and validating CLM5.0 simulation with site observa-tion data,assimilation data(GLDAS-Noah),and satellite remote sensing data(MODIS soil temperature data and ESA CCI-COMBINED soil moisture data)in two stages,this study explores the applicability of CLM5.0 simulation of soil temperature and moisture in the Qinghai-Xizang Plateau.The results indicate that:(1)CLM5.0 can accurately describe the dynamic changes in soil temperature and moisture at stations on the Qinghai-Xizang Plateau.The soil temperature and moisture simulated by CLM5.0 have consistent variation char-acteristics with the observed data and are numerically close.The accuracy of CLM5.0 simulation is higher than that of GLDAS Noah.CLM5.0 provides a more accurate description of soil temperature at the stations.(2)CLM5.0 can accurately describe the soil temperature and moisture characteristics during the freeze-thaw pro-cess in the Qinghai-Xizang Plateau.CLM5.0 simulated soil temperature and moisture show a significant positive correlation with MODIS and ESA CCI-COMBINED remote sensing data on the Qinghai-Xizang Plateau,with correlation coefficients mostly above 0.9.CLM5.0 has relatively better simulation ability for soil temperature in Qinghai-Xizang Plateau areas.CLM5.0 has better simulation ability for soil moisture during thawing periods than during freezing periods.CLM5.0 overestimates the soil temperature of the Qinghai-Xizang Plateau as a whole,with an average deviation mostly between 0～4 ℃.The average deviation of soil moisture simulated by CLM5.0 is mostly between-0.1～0.1 m3·m-3,and the average deviation of soil moisture during thawing period is relatively small.(3)The soil temperature and moisture data from CLM5.0 simulation,GLDAS-Noah,MO-DIS,and ESA CCI-COMBINED remote sensing all have similar spatial distribution characteristics,with higher similarity in the spatial distribution characteristics of soil temperature.CLM5.0 has higher spatial resolution and more precise soil stratification,which can better describe the details of soil temperature and moisture.(4)The CLM5.0 simulation data shows an overall warming and drying trend in the Qinghai-Xizang Plateau,while the MODIS and ESA CCI-COMBINED remote sensing data show an overall warming and moistening trend.The trend of soil temperature changes simulated by CLM5.0 is relatively accurate,while there is a greater deviation in the trend of soil moisture changes.
Qinghai-Xizang PlateauCLM5.0freeze-thaw processsoil temperature and moisture
万方数据
维普
