Precipitation variability in the tropical Andes is strongly influenced by complex topography and regional hydroclimatic processes, yet the spatial organization and temporal evolution of precipitation regimes remain insufficiently characterized. This study identifies dominant precipitation regimes in the Upper Pastaza River Basin, Ecuador, and examines their variability during 1981–2025 using daily precipitation data from the Climate Hazards Group InfraRed Precipitation with Stations (CHIRPS) dataset. CHIRPS estimates were evaluated against observations from three meteorological stations, revealing spatial differences in precipitation estimation accuracy and a general underestimation of monthly precipitation totals. Empirical Orthogonal Function (EOF) analysis and K-means clustering were applied to identify four recurrent precipitation Weather Types (WTs), ranging from a dominant low-intensity regime (WT1), representing approximately 70% of classified days, to a relatively infrequent but intense precipitation regime (WT2), accounting for approximately 1.7%. Seasonal and interannual variability was characterized through regime occurrence frequencies and temporal recurrence patterns. Monotonic trends were assessed using Kendall’s rank correlation coefficient and Sen’s slope estimator, while the burstiness index was used to examine temporal irregularity. A statistically significant positive trend was identified in WT2 occurrence (Kendall’s τ = 0.3830, p = 0.0002), whereas no significant trends were detected for the remaining regimes. Comparison with the recent period (2015–2025), using a consistent classification framework, revealed differences in regime occurrence while preserving broadly similar spatial precipitation patterns. These findings highlight changes in the occurrence of specific precipitation states rather than a generalized redistribution of all regimes, providing insights into hydroclimatic variability across the Andes–Amazon transition zone.

The ozone is a gas composed by three molecules of oxygen which has a great oxidative capacity. This gas can be generated by a nucleus with two electrodes through high voltage in a phenomenon known as corona effect. Actually the conventional nucleus of ozone generators use plane electrodes with a dielectric in the middle of both. A nucleus composed by a mixed ionizador (coil and mesh) is presented as an alternative for an ozone machine in order to take advantage of the individual benefits of each electrode due to its shape and efficiency. A solenoid acts better without dielectric, reducing the consumption, and a mesh improves the air flux. As a result, there is a good production of ozone using this combination of electrodes. However, there are no studies that demonstrate that it is possible to use different types of electrodes in the same ionizador, for this reason in this study will be detected the production of ozone by corona effect in the proposed nucleus and will be approximated its concentration in a closed volume. Keywords: Ozone, corona effect, high voltage, generator, ionization. Resumen El ozono es un gas compuesto por tres moléculas de oxígeno que tiene una gran capacidad oxidativa. Este gas puede ser generado en un núcleo con dos electrodos mediante el uso de altos voltajes en un fenómeno conocido como efecto corona. Actualmente los núcleos de los generadores de ozono convencionales utilizan electrodos planos con un dieléctrico en medio de ellos. Un núcleo compuesto por un ionizador mixto (bobina y malla) se presenta como una alternativa para un ozonificador, con el fin de aprovechar las ventajas individuales de cada electrodo debido a su forma y eficiencia. Un solenoide actúa mejor sin dieléctrico, disminuyendo el consumo, y una malla mejora el flujo de aire. Lo que resulta en una buena producción de ozono utilizando esta combinación de electrodos. Sin embargo, no existen estudios anteriores que demuestran que se puede utilizar diferentes tipos de electrodos en un mismo ionizador, por esta razón en el presente estudio se detectará la producción de ozono por efecto corona en el núcleo mixto propuesto y aproximamos su concentración en un volumen cerrado. Palabras Clave: Ozono, efecto corona, alto voltaje, generador, ionización.