This study updates the multi‐layered Community Land Model (CLM‐ml) for hillslopes and compares predictions from against observations collected in tropical montane rainforest, Costa Rica. Modifications are made in order to capture a wider array of vertical leaf area distributions, predict CO₂ profiles, account for soil respiration, and adjust wind forcings for difficult topographic settings. Test results indicate that the modified multi‐layer CLM model can successfully replicate the shape of various micrometeorological profiles (humidity, CO₂, temperature, and wind speed) under the canopy. In the single‐layer models (CLM4.5 and CLM5), excessive day‐to‐night differences in leaf temperature and leaf wetness were originally noted, but CLM‐ml significantly improved these issues, decreasing the amplitudes of diurnal cycles by 67% and 47%. Sub‐canopy considerations, such as canopy shapes and turbulent transfer parameters, also played a significant role in model performance. More importantly, unlike single layer models, the results that CLM‐ml produces can be compared to variables measured within the canopy to provide far more detailed diagnostic information. Further observations and model developments, aimed at reflecting surface heterogeneity, will be necessary to adequately capture the complexity and the features of the tropical montane rainforest.

中文翻译：

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使用多层CLM（CLM-ML）对热带山前雨林中的微气象变量进行建模

这项研究更新了坡地的多层社区土地模型（CLM-ml），并将来自哥斯达黎加热带山地雨林的观测结果与预测结果进行了比较。进行了修改，以捕获更广泛的垂直叶面积分布，预测CO ₂分布，解释土壤呼吸，并针对困难的地形设置调整风力。测试结果表明，改进的多层CLM模型可以成功复制各种微气象剖面的形状（湿度，CO ₂，温度和风速）。在单层模型（CLM4.5和CLM5）中，最初注意到了叶片温度和叶片湿度的昼夜差异，但是CLM-ml显着改善了这些问题，使昼夜周期的振幅降低了67％， 47％。子冠层的考虑因素，例如冠层形状和湍流传递参数，在模型性能中也起着重要作用。更重要的是，与单层模型不同，可以将CLM-ml产生的结果与冠层中测得的变量进行比较，以提供更详细的诊断信息。为了充分反映热带山地雨林的复杂性和特征，有必要进行进一步的观察和模型开发，以反映地表的非均质性。