为了改进陆面过程模式对青藏高原高寒草甸下垫面的模拟能力,选取玛曲站、阿柔站、那曲站3个典型高原高寒草甸观测站6-9月的观测资料,特别是实测土壤属性数据,并将实测土壤属性数据代入陆面过程模式CLM4.5(Community Land Model)进行单...为了改进陆面过程模式对青藏高原高寒草甸下垫面的模拟能力,选取玛曲站、阿柔站、那曲站3个典型高原高寒草甸观测站6-9月的观测资料,特别是实测土壤属性数据,并将实测土壤属性数据代入陆面过程模式CLM4.5(Community Land Model)进行单点数值模拟试验,为改进模式参数化方案提供依据。研究表明:(1)CLM4.5模式能较好地再现高寒草甸下垫面的土壤温湿度、辐射通量和湍流通量的季节变化,修改土壤属性后模拟效果明显优于修改前,但较观测值还存在一定偏差。(2)修改土壤属性后CLM4.5模式在玛曲站和那曲站对各层土壤湿度的模拟值更接近观测值,在阿柔站对浅层土壤湿度模拟效果的改善优于深层土壤。修改土壤属性后,模式地表虽然与各站点实际地表更为接近,但对土壤温度的改进不明显。(3)修改土壤属性前后反射辐射的模拟值在三个站点均偏低,但修改土壤属性后模拟效果优于修改前。模式对地表长波辐射的改进不显著,其中阿柔站的模拟值与观测值的相关性较高,且偏差较小。(4)CLM4.5模式对各站感热通量的模拟值均高于观测值,修改土壤属性后,感热通量的模拟值更接近实测值且在玛曲站和那曲站的潜热通量模拟值与观测值更为接近。展开更多
Based on the existing land-surface schemes and models,an improved Land-surface Process Model(LPM-ZD)has been developed.It has the following major characteristics:(1)The combination of physical equations and empirical ...Based on the existing land-surface schemes and models,an improved Land-surface Process Model(LPM-ZD)has been developed.It has the following major characteristics:(1)The combination of physical equations and empirical analytical formulae are used to construct the governing equations of soil temperature and moisture.Higher resolution of model level and physical equations are adopted for the upper soil layers,and for the lower soil layers,lower resolution of model level is adopted and empirical analytical formulae are used.(2)In land surface hydrological process,the sub-grid distribution of rainfall and its effects are taken into account. (3)A simple snow cover submodel has been used,which includes effects of snow cover on soil thermodynamics and hydrology,as well as albedo. By use of this model and three groups of point observation data,a series of“off-line”tests have been carried out.The simulation results indicate that land-surface process model has good performance and can well simulate diurnal and seasonal variation of land surface processes for many kinds of land surface covers(forest,grass,crops and desert)in different climate zone.The results simulated by the model are consistent with the observations.Later,by use of one group of observation data and the model,a series of sensitivity experiments have been done.It is shown that the model is much sensitive to some parameters,such as initial soil moisture,vegetation physical parameters as well as the proportion of the grid covered with rain.Therefore it is much important for land-surface process model to define these parameters as accurately as possible.展开更多
The Land-surface Process Model(LPM-ZD)has been successfully coupled with the regional climate model RegCM2 of NCAR.Then thus-obtained coupled model(CRegCM)has been applied to simulate the climate characteristics of he...The Land-surface Process Model(LPM-ZD)has been successfully coupled with the regional climate model RegCM2 of NCAR.Then thus-obtained coupled model(CRegCM)has been applied to simulate the climate characteristics of heavy rain in middle and East China for three months from May to July 1991.and compared with model output of NCAR-RegCM2 using BATS as land- surface process scheme,abbreviated as NRegCM.The results show that CRegCM has good ability and performance.CRegCM successfully simulates the extreme precipitation event and the simulations of CRegCM for surface temperature and some physical variables related to land surface process are more reasonable than those of NRegCM.展开更多
本文以大气边界层物理、大气动力学、土壤物理、水文学和生物物理等理论为基础,研发了一系列适用于不同时空尺度的大气边界层与陆面物理过程模式:(1)基于地表能量和水分平衡方程,构建了新一代北京大学陆面物理过程模式(Land Surface Phy...本文以大气边界层物理、大气动力学、土壤物理、水文学和生物物理等理论为基础,研发了一系列适用于不同时空尺度的大气边界层与陆面物理过程模式:(1)基于地表能量和水分平衡方程,构建了新一代北京大学陆面物理过程模式(Land Surface Physics Process Model of Peking University,LSMPKU);(2)基于城市街谷冠层结构以及相应物理过程,构建了北京大学单层城市冠层模式(Modified Single Layer Urban Canopy Model of Peking University,UCMPKU);(3)基于计算流体力学理论,构建了北京大学街区尺度模式(Block Scale Model of Peking University,BSMPKU).通过模拟研究表明:上述模式在各自的时空适用尺度上均能很好地模拟出相应尺度上的主要大气物理过程,在与其他同类模式的对比实验中表现出明显的改进和提高.展开更多
Response and feedback of land surface research priorities in the field of geoscience. The process to climate change is one of the current study paid more attention to the impacts of global change on land surface proce...Response and feedback of land surface research priorities in the field of geoscience. The process to climate change is one of the current study paid more attention to the impacts of global change on land surface process, but the feedback of land surface process to climate change has been poorly understood. It is becoming more and more meaningful under the framework of Earth system science to understand systematically the relationships between agricultural phenology dynamic and biophysical process, as well as the feedback on climate. In this paper, we summarized the research progress in this field, including the fact of agricultural phenology change, parameterization of phenology dynamic in land surface progress model, the influence of agricultural phenology dynamic on biophysical process, as well as its feedback on climate. The results showed that the agriculture phenophase, represented by the key phenological phases such as sowing, flowering and maturity, had shifted significantly due to the impacts of climate change and agronomic management. The digital expressions of land surface dynamic process, as well as the biophysical process and atmospheric process, were improved by coupling phenology dynamic in land surface model. The agricultural phenology dynamic had influenced net radiation, latent heat, sensible heat, albedo, temperature, precipitation, circulation, playing an important role in the surface energy partitioning and climate feedback. Considering the importance of agricultural phenology dynamic in land surface biophysical process and climate feedback, the following research priorities should be stressed： （1） the interactions between climate change and land surface phenology dynamic; （2） the relations between agricultural phenology dynamic and land surface reflectivity at different spectrums; （3） the contributions of crop physiology characteristic changes to land surface biophysical process; （4） the regional differences of climate feedbacks from phenology dynamic in different climate zo展开更多
文摘为了改进陆面过程模式对青藏高原高寒草甸下垫面的模拟能力,选取玛曲站、阿柔站、那曲站3个典型高原高寒草甸观测站6-9月的观测资料,特别是实测土壤属性数据,并将实测土壤属性数据代入陆面过程模式CLM4.5(Community Land Model)进行单点数值模拟试验,为改进模式参数化方案提供依据。研究表明:(1)CLM4.5模式能较好地再现高寒草甸下垫面的土壤温湿度、辐射通量和湍流通量的季节变化,修改土壤属性后模拟效果明显优于修改前,但较观测值还存在一定偏差。(2)修改土壤属性后CLM4.5模式在玛曲站和那曲站对各层土壤湿度的模拟值更接近观测值,在阿柔站对浅层土壤湿度模拟效果的改善优于深层土壤。修改土壤属性后,模式地表虽然与各站点实际地表更为接近,但对土壤温度的改进不明显。(3)修改土壤属性前后反射辐射的模拟值在三个站点均偏低,但修改土壤属性后模拟效果优于修改前。模式对地表长波辐射的改进不显著,其中阿柔站的模拟值与观测值的相关性较高,且偏差较小。(4)CLM4.5模式对各站感热通量的模拟值均高于观测值,修改土壤属性后,感热通量的模拟值更接近实测值且在玛曲站和那曲站的潜热通量模拟值与观测值更为接近。
文摘Based on the existing land-surface schemes and models,an improved Land-surface Process Model(LPM-ZD)has been developed.It has the following major characteristics:(1)The combination of physical equations and empirical analytical formulae are used to construct the governing equations of soil temperature and moisture.Higher resolution of model level and physical equations are adopted for the upper soil layers,and for the lower soil layers,lower resolution of model level is adopted and empirical analytical formulae are used.(2)In land surface hydrological process,the sub-grid distribution of rainfall and its effects are taken into account. (3)A simple snow cover submodel has been used,which includes effects of snow cover on soil thermodynamics and hydrology,as well as albedo. By use of this model and three groups of point observation data,a series of“off-line”tests have been carried out.The simulation results indicate that land-surface process model has good performance and can well simulate diurnal and seasonal variation of land surface processes for many kinds of land surface covers(forest,grass,crops and desert)in different climate zone.The results simulated by the model are consistent with the observations.Later,by use of one group of observation data and the model,a series of sensitivity experiments have been done.It is shown that the model is much sensitive to some parameters,such as initial soil moisture,vegetation physical parameters as well as the proportion of the grid covered with rain.Therefore it is much important for land-surface process model to define these parameters as accurately as possible.
基金This work is supported by the National Key Research Project 96-908-02-04.
文摘The Land-surface Process Model(LPM-ZD)has been successfully coupled with the regional climate model RegCM2 of NCAR.Then thus-obtained coupled model(CRegCM)has been applied to simulate the climate characteristics of heavy rain in middle and East China for three months from May to July 1991.and compared with model output of NCAR-RegCM2 using BATS as land- surface process scheme,abbreviated as NRegCM.The results show that CRegCM has good ability and performance.CRegCM successfully simulates the extreme precipitation event and the simulations of CRegCM for surface temperature and some physical variables related to land surface process are more reasonable than those of NRegCM.
文摘本文以大气边界层物理、大气动力学、土壤物理、水文学和生物物理等理论为基础,研发了一系列适用于不同时空尺度的大气边界层与陆面物理过程模式:(1)基于地表能量和水分平衡方程,构建了新一代北京大学陆面物理过程模式(Land Surface Physics Process Model of Peking University,LSMPKU);(2)基于城市街谷冠层结构以及相应物理过程,构建了北京大学单层城市冠层模式(Modified Single Layer Urban Canopy Model of Peking University,UCMPKU);(3)基于计算流体力学理论,构建了北京大学街区尺度模式(Block Scale Model of Peking University,BSMPKU).通过模拟研究表明:上述模式在各自的时空适用尺度上均能很好地模拟出相应尺度上的主要大气物理过程,在与其他同类模式的对比实验中表现出明显的改进和提高.
基金China Postdoctoral Science Foundation, No.2016M601115 National Natural Science Foundation of China, No.41571088, No.41371002
文摘Response and feedback of land surface research priorities in the field of geoscience. The process to climate change is one of the current study paid more attention to the impacts of global change on land surface process, but the feedback of land surface process to climate change has been poorly understood. It is becoming more and more meaningful under the framework of Earth system science to understand systematically the relationships between agricultural phenology dynamic and biophysical process, as well as the feedback on climate. In this paper, we summarized the research progress in this field, including the fact of agricultural phenology change, parameterization of phenology dynamic in land surface progress model, the influence of agricultural phenology dynamic on biophysical process, as well as its feedback on climate. The results showed that the agriculture phenophase, represented by the key phenological phases such as sowing, flowering and maturity, had shifted significantly due to the impacts of climate change and agronomic management. The digital expressions of land surface dynamic process, as well as the biophysical process and atmospheric process, were improved by coupling phenology dynamic in land surface model. The agricultural phenology dynamic had influenced net radiation, latent heat, sensible heat, albedo, temperature, precipitation, circulation, playing an important role in the surface energy partitioning and climate feedback. Considering the importance of agricultural phenology dynamic in land surface biophysical process and climate feedback, the following research priorities should be stressed： （1） the interactions between climate change and land surface phenology dynamic; （2） the relations between agricultural phenology dynamic and land surface reflectivity at different spectrums; （3） the contributions of crop physiology characteristic changes to land surface biophysical process; （4） the regional differences of climate feedbacks from phenology dynamic in different climate zo
