| 地表非均匀性对区域平均水分通量参数化的影响 |
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| 引用本文： | 刘晶淼,丁裕国,周秀骥,汪方.地表非均匀性对区域平均水分通量参数化的影响[J].气象学报,2003,61(6):712-717. |
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| 作者姓名： | 刘晶淼 丁裕国 周秀骥 汪方 |
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| 作者单位： | 1. 中国气象科学研究院,北京,100081
2. 南京气象学院,南京,210044 |
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| 基金项目： | 国家重大基础研究项目 (G19980 40 911)，国家自然科学基金 (4 0 2 75 0 3 0 ) |
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| 摘 要： | 次网格尺度地表非均匀性对于网格区平均通量具有重要影响。若将网格区视为均一地表 ,并不能真实描述地 气通量交换过程 ,且可造成很大误差。文中从理论上证明 ,区域平均水分通量的变化率可分解为两部分 :第一部分为区域水分通量的算术平均变化率 ;第二部分为非均匀性所引起的水分通量变化率扰动 ,它与区域内土壤水分空间分布的变差系数有关。数值试验表明 ,地表土壤水分的水平空间变差系数集中反映了区域内土壤水分分布的非均匀程度 ,不同土壤对同样的非均匀程度其敏感性是不同的。变差系数愈大 ,非均匀性愈强 ,在相同的土壤水分平均值下 ,不同土壤类型对地表非均匀程度的敏感性并不相同。例如沙土和粘土受非均匀性的影响就可相差数十倍。
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| 关 键 词： | 地表非均匀性 次网格尺度 地-气平均通量 统计特征值 |
| 收稿时间： | 2003/3/12 0:00:00 |
| 修稿时间： | 2003年3月12日 |
THE INFLUENCE OF LAND SURFACE HETEROGENEITY ON PARAMETERIZATION OF REGIONAL MEAN WATER VAPOR FLUX |
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| Liu Jingmiao,Ding Yuguo,Zhou Xiuji and Wang Fang.THE INFLUENCE OF LAND SURFACE HETEROGENEITY ON PARAMETERIZATION OF REGIONAL MEAN WATER VAPOR FLUX[J].Acta Meteorologica Sinica,2003,61(6):712-717. |
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| Authors: | Liu Jingmiao Ding Yuguo Zhou Xiuji and Wang Fang |
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| Institution: | Chinese Academy of Meteorological Sciences, Beijing, 100081;Nanjing Institute of Meteorology, Nanjing, 210044;Chinese Academy of Meteorological Sciences, Beijing, 100081;Nanjing Institute of Meteorology, Nanjing, 210044 |
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| Abstract: | In this paper it is proved theoretically that the variation ratio of regional mean water vapor flux can be divided into two components: the variation ratio of mathematical mean of regional mean water vapor flux for a region and, the disturbance variation ratio contributed by land surface heterogeneity, which is mainly influenced by variety coefficient of special distribution of soil moisture in the near surface soil layer in the region. It is demonstrated by numerical experiment that the variety coefficient of special distribution of soil moisture content can be used to denote the heterogeneity of soil water content in a spatial region, and the contribution of land surface heterogeneity of soil moisture to the variation ratio of regional mean water vapor flux are also different for diverse soil types. For the same mean of soil water content, the sensitivity of variation ratio of regional mean water vapor flux to land surface heterogeneity of soil moisture is dissimilar completely for different soil types. From this study it can be concluded that the heterogeneous soil moisture distribution on sub-grid scale region imposes important influence on estimation of grid-mean water vapor flux. The heterogeneity of soil moisture in near land surface layer on sub-grid scale should be taking into account in estimation of grid mean water vapor flux in land surface process model. The connotative un-realistic hypothesis of homogeneous soil moisture on grid scale region may make un-neglectable error for the estimations of regional mean water vapor flux. |
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| Keywords: | Heterogeneity of land surface Sub-grid scale Mean fluxes Statistical characteristics |
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