Browsing by Author "Del Rio López, Camilo"

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    Observation-driven model for calculating water-harvesting potential from advective fog in (semi-)arid coastal regions
    (COPERNICUS GESELLSCHAFT MBH, 2025) Lobos Roco, Felipe Andrés; Vila-Guerau de Arellano, Jordi; Del Rio López, Camilo
    Motivated by the need to find complementary water sources in (semi-)arid regions, we develop and assess an observation-driven model to calculate fog-harvesting water potential. We aim to integrate this model with routine meteorological data collected under complex meteorological and topographic conditions to characterize the advective fog phenomenon. Based on the mass balance principle, the Advective fog Model for (semi-)Arid Regions Under climate change (AMARU) offers insights into fog-water-harvesting volumes across temporal and spatial domains. The model is based on a simple thermodynamic approach to calculate the dependence of the liquid water content (rl) on height. Based on climatological fog collection records, we introduce an empirical efficiency coefficient. When combined with rl, this coefficient facilitates the estimation of fog-harvesting volumes (L m-2). AMARU's outputs are validated against in situ observations collected over Chile's coastal (semi-)arid regions at various elevations and during various years (2018-2023). The model's representations of the seasonal cycle of fog harvesting follow observations, with errors of similar to 10 %. The model satisfactorily estimates the maximum rl (similar to 0.8 g kg-1) available for fog harvesting in the vertical column. To assess spatial variability, we combine the model with satellite-retrieved data, enabling the mapping of fog-harvesting potential along the Atacama coast. Our approach enables the application of the combined observation-AMARU model to other (semi-)arid regions worldwide that share similar conditions. Through the quantification of fog harvesting, our model contributes to water planning, ecosystem delimitation efforts, and the study of the climatological evolution of cloud water, among others.
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    Remote sensing based mapping of Tillandsia fields-A semi-automatic detection approach in the hyperarid coastal Atacama Desert, northern Chile
    (2022) Mikulane, Signe; Siegmund, Alexander; Del Rio López, Camilo; Koch, Marcus A.; Osses Mc Intyre, Pablo Eugenio; García Barriga, Juan Luis
    Unique fog ecosystems that occur inland along the Chilean coastal desert are dominated by Tillandsia landbeckii. The average annual precipitation in this hyperarid area lies below 1 mm per year. Tillandsia are specialized in the foliar uptake of fog as a main source of water. The detailed mapping of the distribution of Tillandsia is lacking, making it difficult to understand their geo-ecological niche and to determine the impacts that climate change may have on this species. The objective of this study is to create a detailed spatial distribution of Tillandsia in the Atacama Desert in northern Chile based on remote sensing semi-automatic detection process. For this purpose, high-resolution WorldView-3 optical satellite data has been acquired. The extraction of Tillandsia was done with ENVI Deep Learning tools. As a result, a map of Tillandsia has been created. Several fields were found between Cerro Huantajaya in the north and Cerro Soronal in the south in the study area between 800 and 1300 m a.s.l. For validation purposes ground truth data has been used. The overall accuracy of this classification is 92.02%. The results can be used as a basis for geo-ecological niche modeling, further monitoring and for the development of conservation strategies.
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    Synoptic control of the spatiotemporal variability of fog and low clouds under ENSO phenomena along the Chilean coast (17°-36° S)
    (2024) Espinoza Escobedo, Vicente Patricio; Lobos Roco, Felipe Andrés; Del Rio López, Camilo
    The northern and central coasts of Chile have an extensive semi-permanent layer of stratocumulus clouds that produce fog on land, a crucial resource for water-stressed areas. This study examines the spatio-temporal variability of fog and low clouds (FLC) across four climatic zones (17°S-36°S) characterized by arid conditions. Our analysis aims to elucidate the relationship between FLC patterns and the El Niño-Southern Oscillation (ENSO) phenomenon based on 25 years (1998–2022) of GOES satellite images. The variability of FLC shows a marked, although spatially asymmetric, seasonal cycle, with a subtle positive trend in the long-term. Our results suggest that the presence of FLC is controlled by the strength of the thermal inversion (correlation coefficient, r = 0.7), which, in turn, depends on the sea surface temperature (SST) and the subsidence. Specifically, FLC patterns are controlled by SST in the north (r = −0.9) and by subsidence intensity in the south (r = 0.9). Furthermore, our analysis indicates a potential link between ENSO and FLC, which alters the SST-subsidence equilibrium. At 20°S, warm phases of ENSO lead to increased FLC during the summer and decreased FLC during the winter. Conversely, at 30°S, warm phases result in decreased FLC during the summer and increased FLC during the winter. However, during cold phases, this trend is reversed. At 20°S, FLC decreases in summer and increases in winter, while at 30°S, FLC increases in summer and decreases in winter. In summary, our study offers a novel perspective on understanding the large-scale dynamics associated with FLC frequency along the central and northern coasts of Chile, including FLC underlying mechanisms and the long-term influence exerted by ENSO on the phenomenon.