TY - GEN A1 - Seidel, Jochen A1 - Trachte, Katja A1 - Orellana-Alvear, Johanna A1 - Figueroa, Rafael A1 - Célleri, Rolando A1 - Bendix, Jörg A1 - Fernandez, Ciro A1 - Huggel, Christian T1 - Precipitation Characteristics at Two Locations in the Tropical Andes by Means of Vertically Pointing Micro-Rain Radar Observations T2 - Remote Sensing N2 - In remote areas with steep topography, such as the Tropical Andes, reliable precipitation data with a high temporal resolution are scarce. Therefore, studies focusing on the diurnal properties of precipitation are hampered. In this paper, we investigated two years of data from Micro-Rain Radars (MRR) in Cuenca, Ecuador, and Huaraz, Peru, from February 2017 to January 2019. This data allowed for a detailed study on the temporal precipitation characteristics, such as event occurrences and durations at these two locations. Our results showed that the majority of precipitation events had durations of less than 3 h. In Huaraz, precipitation has a distinct annual and diurnal cycle where precipitation in the rainy season occurred predominantly in the afternoon. These annual and diurnal cycles were less pronounced at the site in Cuenca, especially due to increased nocturnal precipitation events compared to Huaraz. Furthermore, we used a fuzzy logic classification of fall velocities and rainfall intensities to distinguish different precipitation types. This classification showed that nightly precipitation at both locations was predominantly stratiform, whereas (thermally induced) convection occurred almost exclusively during the daytime hours. KW - micro-rain radar KW - Tropical Andes KW - diurnal precipitation characteristics Y1 - 2019 U6 - https://doi.org/10.3390/rs11242985 VL - 11 IS - 24 ER - TY - GEN A1 - Carrillo-Rojas, Galo A1 - Schulz, Hans Martin A1 - Orellana-Alvear, Johanna A1 - Ochoa‐Sánchez, Ana A1 - Trachte, Katja A1 - Célleri, Rolando A1 - Bendix, Jörg T1 - Atmosphere-surface fluxes modeling for the high Andes: The case of páramo catchments of Ecuador T2 - Science of the Total Environment N2 - Interest in atmosphere-surface flux modeling over the mountainous regions of the globe has increased recently, with a major focus on the prediction of water, carbon and other functional indicators in natural and disturbed conditions. However, less research has been centered on exploring energy fluxes (net radiation; sensible, latent and soil heat) and actual evapotranspiration (ETa) over the Neotropical Andean biome of the páramo. The present study assesses the implementation and parameterization of a state-of-art Land-Surface Model (LSM) for simulation of these fluxes over two representative páramo catchments of southern Ecuador. We evaluated the outputs of the LSM Community Land Model (CLM ver. 4.0) with (i) ground-level flux observations from the first (and highest) Eddy Covariance (EC) tower of the Northern Andean páramos; (ii) spatial ETa estimates from the energy balance-based model METRIC (based on Landsat imagery); and (iii) derived ETa from the closure of the water balance (WB). CLM’s energy predictions revealed a significant underestimation on net radiation, which impacts the sensible and soil heat fluxes (underestimation), and delivers a slight overestimation on latent heat flux. Modeled CLM ETa showed acceptable goodness-of-fit (Pearson R = 0.82) comparable to ETa from METRIC (R = 0.83). Contrarily, a poor performance of ETa WB was observed (R = 0.46). These findings provide solid evidence on the CLM’s accuracy for the ETa modeling, and give insights in the selection of other ETa methods. The study contributes to a better understanding of ecosystem functioning in terms of water loss through evaporative processes, and might help in the development of future LSMs’ implementations focused on climate / land use change scenarios for the páramo. KW - Tropical Andes KW - Páramo KW - CLM KW - METRIC KW - Evapotranspiration KW - Eddy covariance Y1 - 2020 U6 - https://doi.org/10.1016/j.scitotenv.2019.135372 SN - 0048-9697 IS - 704 ER - TY - GEN A1 - Campozano, Lenin A1 - Trachte, Katja A1 - Célleri, Rolando A1 - Samaniego, Esteban A1 - Bendix, Jörg A1 - Albuja, Cristóbal A1 - Mejia, John F. T1 - Climatology and Teleconnections of Mesoscale Convective Systems in an Andean Basin in Southern Ecuador: The Case of the Paute Basin T2 - Advances in Meteorology N2 - Mesoscale convective systems (MCSs) climatology, the thermodynamic and dynamical variables, and teleconnections influencing MCSs development are assessed for the Paute basin (PB) in the Ecuadorian Andes from 2000 to 2009. *e seasonality of MCSs occurrence shows a bimodal pattern, with higher occurrence during March-April (MA) and October-November (ON), analogous to the regional rainfall seasonality. *e diurnal cycle of MCSs shows a clear nocturnal occurrence, especially during the MA and ON periods. Interestingly, despite the higher occurrence of MCSs during the rainy seasons, the monthly size relative frequency remains fairly constant throughout the year. On the east of the PB, the persistent high convective available potential and low convective inhibition values from midday to nighttime are likely related to the nocturnal development of the MCSs. A significant positive correlation between the MCSs occurrence to the west of the PB and the Trans-Niño index was found, suggesting that ENSO is an important source of interannual variability of MCSs frequency with increasing development of MCSs during warm ENSO phases. On the east of the PB, the variability of MCSs is positively correlated to the tropical Atlantic sea surface temperature anomalies south of the equator, due to the variability of the Atlantic subtropical anticyclone, showing main departures from this relation when anomalous conditions occur in the tropical Pacific due to ENSO. Y1 - 2018 U6 - https://doi.org/10.1155/2018/4259191 VL - 2018 IS - 3 ER - 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 - Campozano, Lenin A1 - Célleri, Rolando A1 - Trachte, Katja A1 - Bendix, Jörg A1 - Samaniego, Esteban T1 - Rainfall and Cloud Dynamics in the Andes: A Southern Ecuador Case Study T2 - Advances in Meteorology N2 - Mountain regions worldwide present a pronounced spatiotemporal precipitation variability, which added to scarce monitoring networks limits our understanding of the generation processes involved. To improve our understanding of clouds and precipitation dynamics and cross-scale generation processes in mountain regions, we analyzed spatiotemporal rainfall patterns using satellite cloud products (SCP) in the Paute basin (900–4200 m a.s.l. and 6481 km2) in the Andes of Ecuador. Precipitation models, using SCP and GIS data, reveal the spatial extension of three regimes: a three-modal (TM) regime present across the basin, a bimodal (BM) regime, along sheltered valleys, and a unimodal (UM) regime at windward slopes of the eastern cordillera. Subsequently, the spatiotemporal analysis using synoptic information shows that the dry season of the BM regime during boreal summer is caused by strong subsidence inhibiting convective clouds formation. Meanwhile, in UM regions, low advective shallow cap clouds mainly cause precipitation, influenced by water vapor from the Amazon and enhanced easterlies during boreal summer. TM regions are transition zones from UM to BM and zones on the windward slopes of the western cordillera. These results highlight the suitability of satellite and GIS data-driven statistical models to study spatiotemporal rainfall seasonality and generation processes in complex terrain, as the Andes. Y1 - 2016 U6 - https://doi.org/10.1155/2016/3192765 VL - 2016 ER - TY - GEN A1 - Urgilés, Gabriela A1 - Célleri, Rolando A1 - Trachte, Katja A1 - Bendix, Jörg A1 - Orellana-Alvear, Johanna T1 - Clustering of Rainfall Types Using Micro Rain Radar and Laser Disdrometer Observations in the Tropical Andes T2 - Remote Sensing N2 - Lack of rainfall information at high temporal resolution in areas with a complex topography as the Tropical Andes is one of the main obstacles to study its rainfall dynamics. Furthermore, rainfall types (e.g., stratiform, convective) are usually defined by using thresholds of some rainfall characteristics such as intensity and velocity. However, these thresholds highly depend on the local climate and the study area. In consequence, these thresholds are a constraining factor for the rainfall class definitions because they cannot be generalized. Thus, this study aims to analyze rainfall-event types by using a data-driven clustering approach based on the k-means algorithm that allows accounting for the similarities of rainfall characteristics of each rainfall type. It was carried out using three years of data retrieved from a vertically pointing Micro Rain Radar (MRR) and a laser disdrometer. The results show two main rainfall types (convective and stratiform) in the area which highly differ in their rainfall features. In addition, a mixed type was found as a subgroup of the stratiform type. The stratiform type was found more frequently throughout the year. Furthermore, rainfall events of short duration (less than 70 min) were prevalent in the study area. This study will contribute to analyze the rainfall formation processes and the vertical profile. KW - rainfall types KW - k-means KW - micro rain radar KW - laser disdrometer KW - rainfall characteristics KW - tropical Andes Y1 - 2021 U6 - https://doi.org/10.3390/rs13050991 VL - 13 IS - 5 ER -