数值模拟方法在研究长时间的气候变化上扮演着重要角色。一直以来,数值模式模拟年代际气候变化如太平洋年代际震荡(PDO)的位相转换存在巨大挑战。本文利用自然资源部第一海洋研究所研发的地球系统模式(First Institute of Oceanography-...数值模拟方法在研究长时间的气候变化上扮演着重要角色。一直以来,数值模式模拟年代际气候变化如太平洋年代际震荡(PDO)的位相转换存在巨大挑战。本文利用自然资源部第一海洋研究所研发的地球系统模式(First Institute of Oceanography-Earth System Model Version 2,FIO-ESM v2.0)145年(1870–2014年)历史气候模拟试验结果,结合再分析资料和另外两个地球系统模式结果,分析评估了该模式对太平洋年代际振荡的模拟能力。研究发现,FIO-ESM v2.0能够再现历史时期PDO的空间模态分布特征,其PDO指数具有10~30年的周期变化特征,同时于1960年以后能刻画出与再分析数据结果相近的PDO位相转变特征。研究表明,FIO-ESM v2.0能够较为准确地模拟出PDO的位相转变特征。另外,本文还评估了该模式对大气环流模态的模拟能力及其与PDO之间的关系,以及该模式模拟PDO的可能机制。该模式的PDO与大气环流的阿留申低压模态相关。进一步的分析表明,平流作用和热通量是关键年代际海域海温异常振幅的主要因素,而罗斯贝波西传时间则可能是影响PDO位相转变的关键因素。展开更多
Accurate estimations of evapotranspiration(ET)are essential for understanding land-atmosphere coupling and atmosphere-underlying surface energy and water vapor exchanges.Based on input data processing,this paper simul...Accurate estimations of evapotranspiration(ET)are essential for understanding land-atmosphere coupling and atmosphere-underlying surface energy and water vapor exchanges.Based on input data processing,this paper simulates the temporal and spatial variation of ET in the Dajiuhu Basin from 1990 to 2018 using the BEPS-Terrain Lab V2.0 model.Compared with the ET measured by an eddy covariance(EC)tower,the model explained 80.1%of the ET variation.From 1990 to 2018,the average annual ET in the Dajiuhu Basin was 1262.7 mm/yr indicating a downward trend(–27.12 mm/yr).In 2005,a sudden change point was observed based on the Mann-Kendall(MK)test and 3-year moving t-test.Around 2005,the downward trend in ET slowed and the proportional trend of ET to precipitation changed from upward trend to downward trend.Regarding spatial distribution,the ET in the basin’s central part was smaller than that in the basin’s surrounding area,the ET of the southern slope was higher than that of the northern slope,and the decrease in the ET rate on the sunny side was lower than that on the shady side.ET decreased as the elevation increased,with the fastest decrease observed between 2184 and 2384 m.For different landcover types,the average ET exhibited the following order:deciduous forest>mixed forest>wetland>grass>agriculture land.Decreased solar radiation is the main reason for the decreased ET in the Dajiuhu Basin,followed by increased wind speed and relative humidity,which together contribute 83.9%to the ET trend.This paper provides a theoretical basis for the study of ET changes and the mechanism of ET and provides a decision-making reference for water resource management in the Dajiuhu Basin and even the South-to-North Water Transfer Project.展开更多
文摘数值模拟方法在研究长时间的气候变化上扮演着重要角色。一直以来,数值模式模拟年代际气候变化如太平洋年代际震荡(PDO)的位相转换存在巨大挑战。本文利用自然资源部第一海洋研究所研发的地球系统模式(First Institute of Oceanography-Earth System Model Version 2,FIO-ESM v2.0)145年(1870–2014年)历史气候模拟试验结果,结合再分析资料和另外两个地球系统模式结果,分析评估了该模式对太平洋年代际振荡的模拟能力。研究发现,FIO-ESM v2.0能够再现历史时期PDO的空间模态分布特征,其PDO指数具有10~30年的周期变化特征,同时于1960年以后能刻画出与再分析数据结果相近的PDO位相转变特征。研究表明,FIO-ESM v2.0能够较为准确地模拟出PDO的位相转变特征。另外,本文还评估了该模式对大气环流模态的模拟能力及其与PDO之间的关系,以及该模式模拟PDO的可能机制。该模式的PDO与大气环流的阿留申低压模态相关。进一步的分析表明,平流作用和热通量是关键年代际海域海温异常振幅的主要因素,而罗斯贝波西传时间则可能是影响PDO位相转变的关键因素。
基金Under the auspices of National Natural Science Foundation of China(No.41201429)Independent Research Funds of the State Key Laboratory of Biogeology and Environmental Geology(No.GKZ17Y651)Fundamental Research Funds of Geological Processes,Resources and Environment in the Yangtze Basin(No.CUGCJ1808)。
文摘Accurate estimations of evapotranspiration(ET)are essential for understanding land-atmosphere coupling and atmosphere-underlying surface energy and water vapor exchanges.Based on input data processing,this paper simulates the temporal and spatial variation of ET in the Dajiuhu Basin from 1990 to 2018 using the BEPS-Terrain Lab V2.0 model.Compared with the ET measured by an eddy covariance(EC)tower,the model explained 80.1%of the ET variation.From 1990 to 2018,the average annual ET in the Dajiuhu Basin was 1262.7 mm/yr indicating a downward trend(–27.12 mm/yr).In 2005,a sudden change point was observed based on the Mann-Kendall(MK)test and 3-year moving t-test.Around 2005,the downward trend in ET slowed and the proportional trend of ET to precipitation changed from upward trend to downward trend.Regarding spatial distribution,the ET in the basin’s central part was smaller than that in the basin’s surrounding area,the ET of the southern slope was higher than that of the northern slope,and the decrease in the ET rate on the sunny side was lower than that on the shady side.ET decreased as the elevation increased,with the fastest decrease observed between 2184 and 2384 m.For different landcover types,the average ET exhibited the following order:deciduous forest>mixed forest>wetland>grass>agriculture land.Decreased solar radiation is the main reason for the decreased ET in the Dajiuhu Basin,followed by increased wind speed and relative humidity,which together contribute 83.9%to the ET trend.This paper provides a theoretical basis for the study of ET changes and the mechanism of ET and provides a decision-making reference for water resource management in the Dajiuhu Basin and even the South-to-North Water Transfer Project.
