TY - GEN A1 - Bendix, Jörg A1 - Fries, Andreas A1 - Zárate, Jorge A1 - Trachte, Katja A1 - Rollenbeck, Rütger A1 - Pucha-Cofrep, Franz A1 - Paladines, Renzo A1 - Palacios, Ivan A1 - Orellana-Alvear, Johanna A1 - Oñate-Valdivieso, Fernando A1 - Naranjo, Carlos A1 - Mendoza, Leonardo A1 - Mejia, Diego A1 - Guallpa, Mario A1 - Gordillo, Francisco A1 - Gonzalez-Jaramillo, Victor A1 - Dobbermann, Maik A1 - Célleri, Rolando A1 - Carrillo, Carlos A1 - Araque, Augusto A1 - Achilles, Sebastian T1 - RadarNet-Sur First Weather Radar Network in Tropical High Mountains T2 - Bulletin of the American Meteorological Society N2 - Weather radar networks are indispensable tools for forecasting and disaster prevention in industrialized countries. However, they are far less common in the countries of South America, which frequently suffer from an underdeveloped network of meteorological stations. To address this problem in southern Ecuador, this article presents a novel radar network using cost-effective, single-polarization, X-band technology: the RadarNet-Sur. The RadarNet-Sur network is based on three scanning X-band weather radar units that cover approximately 87,000 km2 of southern Ecuador. Several instruments, including five optical disdrometers and two vertically aligned K-band Doppler radar profilers, are used to properly (inter) calibrate the radars. Radar signal processing is a major issue in the high mountains of Ecuador because cost-effective radar technologies typically lack Doppler capabilities. Thus, special procedures were developed for clutter detection and beam blockage correction by integrating ground-based and satelliteborne measurements. To demonstrate practical applications, a map of areas frequently affected by intense rainfall is presented, based on a time series of one radar that has been in operation since 2002. Such information is of vital importance to, for example, infrastructure management because rain-driven landslides are a major issue for road maintenance and safety throughout Ecuador. The presented case study of exceptionally strong rain events during the recent El Niño in March 2015 highlights the system’s practicality in weather forecasting related to disaster management. For the first time, RadarNet-Sur warrants a spatial-explicit observation of El Niño-related heavy precipitation in a transect from the coast to the highlands in a spatial resolution of 500 m. Y1 - 2017 U6 - https://doi.org/10.1175/BAMS-D-15-00178.1 VL - 98 IS - 6 SP - 1235 EP - 1254 ER - TY - GEN A1 - Limberger, Oliver A1 - Homeier, Jürgen A1 - Farwig, Nina A1 - Pucha-Cofrep, Franz A1 - Fries, Andreas A1 - Leuschner, Christoph A1 - Trachte, Katja A1 - Bendix, Jörg T1 - Classification of Tree Functional Types in a Megadiverse Tropical Mountain Forest from Leaf Optical Metrics and Functional Traits for Two Related Ecosystem Functions T2 - Forests N2 - Few plant functional types (PFTs) with fixed average traits are used in land surface models (LSMs) to consider feedback between vegetation and the changing atmosphere. It is uncertain if highly diverse vegetation requires more local PFTs. Here, we analyzed how 52 tree species of a megadiverse mountain rain forest separate into local tree functional types (TFTs) for two functions: biomass production and solar radiation partitioning. We derived optical trait indicators (OTIs) by relating leaf optical metrics and functional traits through factor analysis. We distinguished four OTIs explaining 38%, 21%, 15%, and 12% of the variance, of which two were considered important for biomass production and four for solar radiation partitioning. The clustering of species-specific OTI values resulted in seven and eight TFTs for the two functions, respectively. The first TFT ensemble (P-TFTs) represented a transition from low to high productive types. The P-TFT were separated with a fair average silhouette width of 0.41 and differed markedly in their main trait related to productivity, Specific Leaf Area (SLA), in a range between 43.6 to 128.2 (cm2/g). The second delineates low and high reflective types (E-TFTs), were subdivided by different levels of visible (VIS) and near-infrared (NIR) albedo. The E-TFTs were separated with an average silhouette width of 0.28 and primarily defined by their VIS/NIR albedo. The eight TFT revealed an especially pronounced range in NIR reflectance of 5.9% (VIS 2.8%), which is important for ecosystem radiation partitioning. Both TFT sets were grouped along elevation, modified by local edaphic gradients and species-specific traits. The VIS and NIR albedo were related to altitude and structural leaf traits (SLA), with NIR albedo showing more complex associations with biochemical traits and leaf water. The TFTs will support LSM simulations used to analyze the functioning of mountain rainforests under climate change. KW - ecosystem productivity KW - energy fluxes KW - leaf hyperspectra KW - functional traits KW - tree functional types KW - tropical forest Y1 - 2021 U6 - https://doi.org/10.3390/f12050649 SN - 1999-4907 VL - 12 IS - 5 ER - TY - GEN A1 - Murkute, Charuta A1 - Sayeed, Mostafa A1 - Pucha-Cofrep, Franz A1 - Carrillo-Rojas, Galo A1 - Homeier, Jürgen A1 - Limberger, Oliver A1 - Fries, Andreas A1 - Bendix, Jörg A1 - Trachte, Katja T1 - Turbulent energy and carbon fluxes in an Andean Montane Forest—energy balance and heat storage T2 - Forests N2 - High mountain rainforests are vital in the global energy and carbon cycle. Understanding the exchange of energy and carbon plays an important role in reflecting responses to climate change. In this study, an eddy covariance (EC) measurement system installed in the high Andean Mountains of southern Ecuador was used. As EC measurements are affected by heterogeneous topography and the vegetation height, the main objective was to estimate the effect of the sloped terrain and the forest on the turbulent energy and carbon fluxes considering the energy balance closure (EBC) and the heat storage. The results showed that the performance of the EBC was generally good and estimated it to be 79.5%. This could be improved when the heat storage effect was considered. Based on the variability of the residuals in the diel, modifications in the imbalances were highlighted. Particularly, during daytime, the residuals were largest (56.9 W/m 2 on average), with a clear overestimation. At nighttime, mean imbalances were rather weak (6.5 W/m 2 ) and mostly positive while strongest underestimations developed in the transition period to morning hours (down to −100 W/m 2 ). With respect to the Monin–Obukhov stability parameter ((z − d)/L) and the friction velocity (u*), it was revealed that the largest overestimations evolved in weak unstable and very stable conditions associated with large u* values. In contrast, underestimation was related to very unstable conditions. The estimated carbon fluxes were independently modelled with a non-linear regression using a light-response relationship and reached a good performance value (R 2 = 0.51). All fluxes were additionally examined in the annual course to estimate whether both the energy and carbon fluxes resembled the microclimatological conditions of the study site. This unique study demonstrated that EC measurements provide valuable insights into land-surface–atmosphere interactions and contribute to our understanding of energy and carbon exchanges. Moreover, the flux data provide an important basis to validate coupled atmosphere ecosystem models. KW - energy balance closure KW - heat storage KW - carbon fluxes KW - eddy covariance KW - Andes Mountains Y1 - 2024 U6 - https://doi.org/10.3390/f15101828 SN - 1999-4907 VL - 15 IS - 10 PB - MDPI ER - TY - GEN A1 - Grigusova, Paulina A1 - Limberger, Oliver A1 - Murkute, Charuta A1 - Pucha-Cofrep, Franz A1 - Gonzalez-Jaramillo, Victor Hugo A1 - Fries, Andreas A1 - Windhorst, David A1 - Breuer, Lutz A1 - Dantas de Paula, Mateus A1 - Hickler, Thomas A1 - Trachte, Katja A1 - Bendix, Jörg T1 - Radiation partitioning in a cloud-rich tropical mountain rain forest of the S-Ecuadorian Andes for use in plot-based land surface modelling T2 - Dynamics of atmospheres and oceans : planetary fluid, climatic and biogeochemical systems N2 - Understanding the partitioning of downward shortwave radiation into direct and diffuse components is essential for modeling ecosystem energy fluxes. Accurate partitioning functions are critical for land surface models (LSMs) coupled with climate models, yet these functions often depend on regional cloud and aerosol conditions. While data for developing semi-empirical partitioning functions are abundant in mid-latitudes, their performance in tropical regions, particularly in the high Andes, remains poorly understood due to scarce ground-based measurements. This study analyzed a unique dataset of shortwave radiation components from a tropical mountain rainforest (MRF) in southern Ecuador, developing and testing a locally adapted partitioning function using Random Forest Regression. The model achieved high accuracy in predicting the percentage of diffuse radiation (%Dif; R²=0.95, RMSE = 5.33, MAE = 3.74) and absolute diffuse radiation (R²=0.99, RMSE = 5.30, MAE = 14). When applied to simulate upward shortwave radiation, the model outperformed commonly used partitioning functions achieving the lowest RMSE (8.62) and MAE (5.82) while matching the highest R² (0.97). These results underscore the importance of regionally adapted radiation partitioning functions for improving LSM performance, particularly in complex tropical environments. The adapted LSM will be further utilized for studies on heat fluxes and carbon sequestration. Y1 - 2025 U6 - https://doi.org/10.1016/j.dynatmoce.2025.101553 SN - 0377-0265 VL - 110 SP - 1 EP - 16 PB - Elsevier CY - Amsterdam ER - TY - GEN A1 - Bendix, Jörg A1 - Limburger, Oliver A1 - Breuer, Lutz A1 - Dantas de Paula, Mateus A1 - Fries, Andreas A1 - Gonzalez-Jaramillo, Victor Hugo A1 - Grigusova, Paulina A1 - Hickler, Thomas A1 - Murkute, Charuta A1 - Pucha-Cofrep, Franz A1 - Trachte, Katja A1 - Windhorst, David T1 - Simulation of latent heat flux over a high altitude pasture in the tropical Andes with a coupled land surface framework T2 - The science of the total environment N2 - 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 R² of 0.8 and an RMSE of 34.0 W m⁻², 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. Y1 - 2025 U6 - https://doi.org/10.1016/j.scitotenv.2025.179510 SN - 1879-1026 VL - 981 SP - 1 EP - 21 PB - Elsevier CY - Amsterdam ER -