Person:
Carrillo Rojas, Galo José

Birth Date

1978-04-28

ORCID

0000-0003-4410-6926

Scopus Author ID

56117784400

Afiliación

Universidad de Cuenca, Facultad de Ciencias Químicas, Cuenca, Ecuador
Universidad de Cuenca, Departamento de Recursos Hídricos y Ciencias Ambientales, Cuenca, Ecuador

País

Ecuador

Organizational Units

Organizational Unit

Facultad de Ciencias Químicas

Fundada en 1955 como la Escuela de Química Industrial, la facultad ha sido un pilar fundamental en la formación de profesionales altamente capacitados, comprometidos con el desarrollo de la ciencia, la educación y el bienestar social. La Facultad de Ciencias Químicas pone a consideración su trabajo académico, investigativo y de vinculación con la sociedad, desarrollado a través de la práctica de una docencia de calidad, investigación e innovación en su área de estudio. Desde su oficio de conocimiento se permite contribuir a la sociedad con cuatro carreras: Bioquímica y Farmacia, Ingeniería Química, Ingeniería Ambiental e Ingeniería Industrial. Su carta de presentación en la Academia, la coloca como una dependencia dinámica, donde confluye la solidez de una trayectoria de más de sesenta años. Aquí se trabaja en una continua formación de pregrado y posgrado de la más alta calidad, mediante la mejora continua con la innovación y a la vanguardia de las ciencias químicas.

Job Title

Profesor (T)

Last Name

Carrillo Rojas

First Name

Galo José

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Now showing 1 - 10 of 17

Evaluation of the Penman-Monteith (FAO 56 PM) Method for Calculating Reference Evapotranspiration Using Limited Data
(INTERNATIONAL MOUNTAIN SOCIETY, 2015-08-01) Córdova Mora, Mario Andrés; Carrillo Rojas, Galo José; Célleri Alvear, Rolando Enrique; Crespo Sánchez, Patricio Javier
(Figure Presented) Reference evapotranspiration (ETo) is often calculated using the Penman-Monteith (FAO 56 PM; Allen et al 1998) method, which requires data on temperature, relative humidity, wind speed, and solar radiation. But in high-mountain environments, such as the Andean páramo, meteorological monitoring is limited and high-quality data are scarce. Therefore, the FAO 56 PM equation can be applied only through the use of an alternative method suggested by the same authors that substitutes estimates for missing data. This study evaluated whether the FAO 56 PM method for estimating missing data can be effectively used for páramo landscapes in the high Andes of southern Ecuador. Our investigation was based on data from 2 automatic weather stations at elevations of 3780 m and 3979 m. We found that using estimated wind speed data has no major effect on calculated ETo but that if solar radiation data are estimated, ETo calculations may be erroneous by as much as 24%; if relative humidity data are estimated, the error may be as high as 14%; and if all data except temperature are estimated, errors higher than 30% may result. Our study demonstrates the importance of using high-quality meteorological data for calculating ETo in the wet páramo landscapes of southern Ecuador.
Atmosphere-surface fluxes modeling for the high Andes: the case of páramo catchments of Ecuador
(2020) Carrillo Rojas, Galo José; Schulz, Hans Martin; Orellana Alvear, Johanna Marlene; Ochoa Sánchez, Ana Elizabeth; Trachte, Katja; Célleri Alvear, Rolando Enrique; Bendix, Jorg
© 2019 Elsevier B.V. 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.
Turbulent energy and carbon fluxes in an andean montane forest—energy balance and heat storage
(2024) Carrillo Rojas, Galo José
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/m2 on average), with a clear overestimation. At nighttime, mean imbalances were rather weak (6.5 W/m2) and mostly positive while strongest underestimations developed in the transition period to morning hours (down to −100 W/m2). 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 (R2 = 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.
Variability in evapotranspiration in the Andean páramo as influenced by fog and rainfall
(2024) Berrones Guapulema, Gina Marcela; Crespo Sánchez, Patricio Javier; Carrillo Rojas, Galo José; Célleri Alvear, Rolando Enrique
Tropical mountains such as the páramos of the Andes, which serve as ‘water towers’ for local communities and downstream cities, are important areas for early detection of climate change. Here, fog and low-intensity rainfall are very common and play a key role in ecohydrological processes. Although evapotranspiration (ET) represents an important part of the water cycle, how ET and fog processes interact and how they affect páramo vegetation and water resources availability are poorly understood. This study investigated the effects of foggy (fog only) and mixed (fog and rainfall) conditions on ET. To determine whether fog significantly reduces ET, we compared ET and meteorological data under these two conditions with those during dry days. We found that on foggy days, when fog was most prevalent in the early morning, ET declined on average by 4% and net radiation (Rn) by 9.2%. Under mixed conditions, daily ET declined by 42% and Rn by 33%. In the páramo, where mean annual precipitation and ET are 1210 and 635 mm, respectively, the estimated annual reduction in ET due to fog and rainfall combined is between 77 and 174 mm. We found that during fog and rainfall mixed conditions, solar radiation was reduced, consequently constraining the energy available for ET while sustaining high relative humidity, ultimately reducing water loss. Our findings, which suggest that the presence of fog and low-intensity rainfall restricts water losses by evaporative demand, contribute to a better understanding of the ecohydrological importance of these water inputs in the Andes.
Improving reference evapotranspiration (ETo) calculation under limited data conditions in the high Tropical Andes
(2022) Carrillo Rojas, Galo José; Córdova Mora, Mario Andrés; Vásquez Ojeda, Cristina Alejandra; Célleri Alvear, Rolando Enrique
The computation of the reference crop evapotranspiration (ETo) using the FAO56 Penman-Monteith equation (PM-ETo) requires data on maximum and minimum air temperatures (Tmax, Tmin), relative humidity (RH), solar radiation (Rs), and wind speed (u2). However, the records of meteorological variables are often incomplete or of poor quality. Frequently, in the mountain areas such as those of the Andes, environmental sensors are subject to harsh conditions, due to the diurnal/nocturnal climatic variability causing challenging conditions for meteorological monitoring, which leads to data loss. For high-elevation landscapes like the Andes, the missing variables of vapor pressure deficit and solar radiation cause a high impact on PM-ETo calculation. To assess these limitations, several methods relying on maximum and minimum temperature to estimate the missing variables have been considered in the present investigation. Based on data from three automatic weather stations in the high Tropical Andes (humid páramo, 3298 – 3955 m a.s.l.), we found that the calibration and validation of methods were essential to estimate Rs. Using the (De Jong and Stewart, 1993) (Rs-DS) method we retrieved the highest performance, a RMSE between 2.89 and 3.81 MJ m−2 day−1. Moreover, In the absence of RH observations, replacing the dew point temperature (Tdew) by Tmin was a reliable alternative, when apply the method of (Allen et al., 1998) (VPD-FAO) which showed the highest performance with RMSE between 0.08 and 0.12 kPa. These results yielded highly accurate PM-ETo estimates, with RMSE between 0.29 and 0.34 mm day−1 and RMSE between 0.12 and 0.18 mm day−1, respectively. As expected, when both variables were missing, the ETo calculation increased its error, with an RMSE between 0.32 and 0.42 mm day−1. A proper estimation of ETo in the Andean páramo contributes to improved water productivity for domestic and industrial uses, irrigated agriculture, and hydropower.
The breathing of the andean highlands: net ecosystem exchange and evapotranspiration over the páramo of southern Ecuador
(2019) Carrillo Rojas, Galo José; Silva, Brenner; Rollenbeck, Rütger; Célleri Alvear, Rolando Enrique; Bendix, Jorg
Atmospheric carbon (CO 2) exchange, evapotranspiration (ET) processes, and their interactions with climatic drivers across tropical alpine grasslands are poorly understood. This lack of understanding is particularly evident for the páramo, the highest vegetated frontier in the northern Andes, the main source of water for inter-Andean cities, and a large carbon storage area. Studies of CO 2 and ET fluxes via the standard Eddy Covariance (EC) technique have never been applied to this region, limiting the understanding of diurnal / nocturnal exchanges and budget estimations. In this paper, we report the first EC analysis conducted on the Andean páramo (3765 m a.s.l.); this analysis measured CO 2, ET, and micrometeorological variables over two years (2016–2018) to understand their interactions with climatic / biophysical controls. The páramo was found to be a source of CO 2 and exhibited a net positive exchange …
Impact of electrical energy efficiency programs, case study: food processing companies in Cuenca, Ecuador
(2014-04-01) Carrillo Rojas, Galo José; Andrade Rodas, Juan Manuel; Barragán Escandón, Edgar Antonio; Astudillo Alemán, Ana Lucía
This exploratory study illustrates the effects of the application of electrical energy efficiency programs in 7 food processing companies in Cuenca, Ecuador. The research encompassed phases of diagnosis, intervention and evaluation. A comparative analysis between the companies was conducted: energy consumption versus product volume, energy-quality analysis, relation between compliance/specific energy consumption, and the impact on CO2 emissions. Results revealed that the acceptance to the recommendations of savings is biased by the level of investments and the willing/proneness of the administration. The study showed that interventions had a partial effect on the reduction of the specific energy consumption in 4 companies. In addition, it has obtained a positive effect on the power factor correction in one company and an improvement on the load balance in 5. The research showed the existence of a significant reduction of emissions post-intervention, highlighting the effectiveness of the programs. © The authors; licensee Universidad Nacional de Colombia.
Overcast sky condition prevails on and influences the biometeorology of the tropical Andean Páramos
(2023) Montenegro Díaz, Paola Fernanda; Célleri Alvear, Rolando Enrique; Carrillo Rojas, Galo José
Clouds play a major role in modulating the biometeorological processes. We studied the influence of cloudiness on four biometeorological variables: daily air temperature (Tair), relative humidity (RH), reference evapotranspiration (ETr), and photosynthetic active radiation (PAR), recorded at four sites of Andean Páramos in southern Ecuador during 2.5 to 5.5 years. First, we quantified both the cloud cover percentage (Cloud%) creating cloud masks over the visible bands of Landsat 7 images and the sky condition (KT) using the records of solar and extraterrestrial radiation. Second, we estimated KT from Cloud%. Finally, we quantified Tair, RH, ETr, and PAR under clear, cloudy, and overcast KT and their dependence on KT. The average Cloud% ranged between 65%–76%, and KT corroborated the prevailing overcast sky (between 55% and 72.5% of the days) over the páramos. The proposed model performed well in the sites of calibration (R2 = 0.80; MBE = 0.00; RMSE = 0.05) and validation (R2 = 0.74; MBE = -0.07; RMSE = 0.11). The overcast sky diminished Tair (≤ 10oC), ETr (≤ 1.6 mm day-1), and PAR (4 MJ m-2 day-1) and increased RH (≥ 88%), while the variables showed the opposite behavior during the uncommon clear sky (≤ 5.5% of the days). Thus, mostly the dynamic of RH (R2 ≥ 0.62), ETr (R ≥ 0.85), and PAR (R2 ≥ 0.77) depended on KT. Hence, the prevailing overcast sky influenced the biometeorology of the páramos.
Altitudinal and temporal evapotranspiration dynamics via remote sensing and vegetation index-based modelling over a scarce-monitored, high-altitudinal Andean páramo ecosystem of Southern Ecuador
(2019) Ramón Reinozo, Mayra; Ballari, Daniela Elisabet; Cabrera Cabrera, Juan Geovanny; Crespo Sánchez, Patricio Javier; Carrillo Rojas, Galo José
In the tropical Andes, the paramo ecosystem is known as water towers and the main water supplier for the cities of the Andean region. Nevertheless, considering that evapotranspiration (ET) is the major water loss and the lack of in situ evapotranspiration measurements in high altitudinal paramo ecosystems, ET dynamics on the hydrological regulation remains largely unexplored. Therefore, to close this gap, we focused on a remote sensing approach. This study addressed the altitudinal and temporal dynamics of actual evapotranspiration using a crop coefficient based on a Vegetation Index (VI) model. Enhanced Vegetation Index (EVI), Normalized Difference Vegetation Index (NDVI) and Soil-Adjusted Vegetation Index (SAVI) retrieved from Landsat imagery were evaluated. Four remote sensing images and ground-level meteorological data for a 10-month period were used to create ET maps from each VI. A cubic spline interpolation was used to obtain daily ET time series between two satellite overpass dates. Aggregated monthly values were used to validate against ET calculated from water balance. Results revealed that EVI-based ET outperformed the other VI-based ET. The results showed 30% of subestimation (Pbias%) in relation to the water balance. For upgraded results, an extended satellite images time series and a fine calibration are needed. Regarding the altitudinal variability, ET exhibited a strong dependence on land cover characteristics. Our work provides a plausible method to estimate ET in paramo ecosystems in the absence of ET measurements and with a scarcity of clear sky images, further evaluation is necessary to improve ET estimations using remote sensing in the future.
Estimating turbulent fluxes in the tropical andes
(2020) Córdova Mora, Mario Andrés; Bogerd, Linda; Smeets, Paul; Carrillo Rojas, Galo José
The correct estimation of Sensible Heat Flux (H) and Latent Heat Flux (LE) (i.e., turbulent fluxes) is vital in the understanding of exchange of energy and mass among hydrosphere, atmosphere, and biosphere in an ecosystem. One of the most popular methods to measure these fluxes is the Eddy Covariance (EC) technique; however, there are a number of setbacks to its application, especially in remote and topographically complex terrain such as the higher altitudes of the Andes. Efforts have been made by the scientific community to parameterise these fluxes based on other more commonly measured variables. One of the most widespread methods is the so-called bulk method, which relates average temperature, humidity, and wind vertical profiles to the turbulent fluxes. Another approach to estimate LE is the Penman-Monteith (PM) equation which uses meteorological measurements at a single level. The objective of this study was to validate these methods for the first time in the Tropical Andes in Southern Ecuador (in the páramo ecosystem at 3780 m a.s.l.) using EC and meteorological measurements. It was determined that the bulk method was the best to estimate H, although some adjustments had to be made to the typical assumptions used to estimate surface meteorological values. On the other hand, the PM equation yielded the best LE estimations. For both fluxes, the error in the estimations was within the uncertainty range of the EC measurements. It can be concluded that it is possible to accurately estimate H and LE using the methods described in this paper in this ecosystem when no direct measurements are available.