SENSITIVITY STUDY AND VALIDATION OF A LAND SURFACE PARAMETERIZATION USING THE HAPEX-MOBILHY DATA SET
SENSITIVITY STUDY AND VALIDATION OF A LAND SURFACE PARAMETERIZATION USING THE HAPEX-MOBILHY DATA SET
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DOI：
10.1007/bf00123180
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发表时间：
1990-07-01
影响因子：
4.3
通讯作者：
NOILHAN, J
中科院分区：
文献类型：
--
作者：
JACQUEMIN, B;NOILHAN, J
陆地表面过程的简单参数化，适合两层土壤模型的结构，包括植被的表示，已被设计用于气象模型。在介观模型中实施之前，有必要检查组件并验证整个参数化的良好工作状态。本文的目的是：（i）对模型的各个组成部分进行评估和敏感性研究，指定参数所需的精度； (ii) 根据 HAPEX-MOBILHY 数据集对模型进行微气象验证。首先，我们介绍基本方案。重点是表面电阻的参数化，特别是其与土壤湿度的关系。然后通过一组一维模拟进行敏感性研究，允许地面和大气之间的充分相互作用。在裸露地面上，结果表明土壤质地和初始湿度都会极大地影响模拟结果。潜热通量范围从通过类似开关行为与潜在蒸发相关的潜热通量到干燥土壤的潜热通量。接下来，研究蒸腾植被冠层对所涉及的物理过程和表面能量平衡的影响。强调潜热通量对土壤和冠层参数变化的敏感性；指出了初始平均土壤湿度和植被覆盖的主要影响。 最后，研究了边界层响应各种表面条件的演变。陆地表面方案的验证是在无云的日子里通过日常循环进行的。模拟的湍流通量成功地与玉米田不同生长阶段的微米测量结果进行了比较。在松树林上空，通过考虑大气水分不足的表面电阻的适当参数化，可以获得对湍流通量的正确模拟。
A simple parameterization of land surface processes, amenable to the sructure of a two-layer soil model, including a representation of the vegetation, has been designed for use in meteorological models. Prior to implementation in a mesoscale model, it is necessary to check the components and to verify the good working order of the parameterization as a whole. The aims of this paper then are: (i) evaluation and a sensitivity study of the various components of the model, specifying the needed accuracy for the parameters; (ii) micrometeorological validation of the model against the HAPEX-MOBILHY data set. First, we present the basic scheme. The focus is on the parameterization of surface resistance, and especially on its relationship with soil moisture. A sensitivity study is then performed through a set of one-dimensional simulations which allow a full interaction between the ground and the atmosphere. Above bare ground, it is shown that both soil texture and initial moistue greatly influence the outcome of the simulation. Latent heat flux ranges from that associated with potential evaporation through a switch-like behavior to that of dry soil. Next, the effects of transpiring vegetation canopies on the physical processes involved and the surface energy balance are examined. The sensitivity of the latent heat flux to changes in the soil and canopy parameters is emphasized; the major influence of the initial mean soil moisture and of the vegetation cover is pointed out. Finally, the evolution of the boundary layer in response to various surface conditions is studied. A validation of the land surface scheme is conducted through daily cycles during cloudless days. Simulated turbulent fluxes are successfully compared to micrometerological measurements over a maize field at different growth stages. Over a pine forest, the correct simulation of the turbulent fluxes is obtained with an adequate parameterization of the surface resistance accounting for the atmospheric moisture deficit.