Bendix J, Limberger O, Breuer L, de Paula M Dantas, Fries A, González-Jaramillo V H, Grigusova P, Hickler T, Murkute C, Pucha-Cofrep F, Trachte K, Windhorst D
Laboratory for Climatology and Remote Sensing, Department of Geography, University of Marburg, Deutschhausstr. 12, 35032 Marburg, Germany.
Laboratory for Climatology and Remote Sensing, Department of Geography, University of Marburg, Deutschhausstr. 12, 35032 Marburg, Germany.
Sci Total Environ. 2025 Jun 15;981:179510. doi: 10.1016/j.scitotenv.2025.179510. Epub 2025 May 8.
Latent heat flux is a central element of land-atmosphere interactions under climate change. Knowledge is particularly poor in the biodiversity hotspot of the Andes, where heat flux measurements using eddy covariance stations are scarce and land surface models (LSMs) often oversimplify the complexity of the ecosystems. The main objective of this study is to perform latent heat flux simulations for the tropical South Eastern (SE) Ecuadorian Andes using a coupled LSM framework, and to test the performance with heat flux and soil moisture data collected from a tropical high-altitude pasture. Prior to testing, we applied multi-criteria model calibration of sensitive model parameters, focusing on improving simulated soil water conditions and radiation fluxes as a prerequisite for proper heat flux simulations. The most sensitive parameters to improve soil moisture and radiation flux simulations were soil porosity, saturated hydraulic conductivity, leaf area index, soil colour and NIR (Near Infrared) leaf optical properties. The best calibrated model run showed a very good performance for half-hourly latent heat flux simulations with an R of 0.8 and an RMSE of 34.0 W m, outperforming simulations with uncalibrated and uncoupled LSM simulations in comparable areas. The slight overall overestimation in the simulated latent heat flux can be related to (i) simulation uncertainties in the canopy heat budget, (ii) an imbalance in the observed flux data and (iii) slight overestimations in the simulated soil moisture. Although our study focuses on latent heat fluxes and their relation to simulated radiation fluxes and soil moisture, model outputs of sensible heat fluxes were also discussed. The systematic overestimation of sensible heat flux in the model seems to be mainly a result of overestimated canopy temperatures. The improved simulation for latent heat flux has a high translational potential to support land use strategies in the tropical Andes under climate change.
潜热通量是气候变化下陆地 - 大气相互作用的核心要素。在安第斯山脉的生物多样性热点地区，相关知识尤为匮乏，那里使用涡度协方差站进行的热通量测量稀少，且陆面模型（LSMs）常常过度简化生态系统的复杂性。本研究的主要目标是使用耦合陆面模型框架对厄瓜多尔东南部热带安第斯山脉进行潜热通量模拟，并利用从热带高海拔牧场收集的热通量和土壤湿度数据来测试其性能。在测试之前，我们对敏感模型参数进行了多标准模型校准，重点是改善模拟的土壤水分状况和辐射通量，将其作为进行正确热通量模拟的前提条件。改善土壤湿度和辐射通量模拟最敏感的参数是土壤孔隙率、饱和导水率、叶面积指数、土壤颜色和近红外（NIR）叶片光学特性。校准最佳的模型运行在半小时潜热通量模拟中表现出非常好的性能，R值为0.8，均方根误差为34.0 W m，在可比区域优于未校准和未耦合的陆面模型模拟。模拟潜热通量中总体上轻微的高估可能与以下因素有关：（i）冠层热量收支的模拟不确定性；（ii）观测通量数据的不平衡；（iii）模拟土壤湿度的轻微高估。尽管我们的研究重点是潜热通量及其与模拟辐射通量和土壤湿度的关系，但也讨论了感热通量的模型输出。模型中感热通量的系统性高估似乎主要是冠层温度高估的结果。潜热通量模拟的改进对于支持气候变化下热带安第斯山脉的土地利用策略具有很高的转化潜力。
