Evaluation of the urban tile in MOSES using surface energy balance observations
Evaluation of the urban tile in MOSES using surface energy balance observations
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DOI：
10.1007/s10546-005-9025-5
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发表时间：
2006-03-01
影响因子：
4.3
通讯作者：
Villani, Maria Gabriella
中科院分区：
文献类型：
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作者：
Best, M. J.;Grimmond, C. S. B.;Villani, Maria Gabriella
英国气象局在摩西2.2中为其城市瓷砖引入了一项新计划(气象局地面交换计划2.2版)，该计划目前在气象局业务天气预报模式中实施。在这里，城市瓷砖的性能在两个城市地区进行了评估：墨西哥城市中心的历史核心和加拿大温哥华的一个轻工业场地。这两个地点在建筑结构和平均建筑高度方面存在差异。在这两种情况下，植被覆盖率都不到5%。评估是基于在大约混合高度进行的地面能量平衡通量测量，混合高度是地面方案将通量数据传递到大气模式的位置。在这两个站点，摩西2.2都正确地模拟了净辐射，但在湍流和储存热通量的分配方面，预测值和观测值存在差异。在湍流通量中，潜热通量被低估了约一个数量级。多个模型运行表明，摩西2.2对冠层储热以及空气动力粗糙度长度与换热(温度)长度之比的变化很敏感。当热容数值小于通常认为的这些站点的热容值时，模型的性能最佳。结果表明，目前的方案可能过于简单，可以通过增加模型的复杂性来获得改进。
The UK Met Office has introduced a new scheme for its urban tile in MOSES 2.2 (Met Office Surface Exchange Scheme version 2.2), which is currently implemented within the operational Met Office weather forecasting model. Here, the performance of the urban tile is evaluated in two urban areas: the historic core of downtown Mexico City and a light industrial site in Vancouver, Canada. The sites differ in terms of building structures and mean building heights. In both cases vegetation cover is less than 5%. The evaluation is based on surface energy balance flux measurements conducted at approximately the blending height, which is the location where the surface scheme passes flux data into the atmospheric model. At both sites, MOSES 2.2 correctly simulates the net radiation, but there are discrepancies in the partitioning of turbulent and storage heat fluxes between predicted and observed values. Of the turbulent fluxes, latent heat fluxes were underpredicted by about one order of magnitude. Multiple model runs revealed MOSES 2.2 to be sensitive to changes in the canopy heat storage and in the ratio between the aerodynamic roughness length and that for heat transfer (temperature). Model performance was optimum with heat capacity values smaller than those generally considered for these sites. The results suggest that the current scheme is probably too simple, and that improvements may be obtained by increasing the complexity of the model.