Artículos científicos

Mini-agujero de ozono sobre Río Gallegos en marzo de 2025: caracterización e impacto en la radiación UV

2026-01-16T13:32:24Z

Mini-agujero de ozono sobre Río Gallegos en marzo de 2025: caracterización e impacto en la radiación UV Laino-Baldini, Cristian; Orte, Facundo; Carmona, Facundo; Luccini, Eduardo; Carbajal Benítez, Gerardo; Wolfram, Elián La reducción transitoria pero abrupta de la capa de ozono conocida como “mini-agujero de ozono”, puede incrementar de forma puntual la radiación ultravioleta en superficie, con efectos potenciales sobre la salud y los ecosistemas. En Sudamérica estos fenómenos han sido escasamente documentados, lo que resalta la necesidad de estudios detallados. En este trabajo se presenta la primera caracterización de un mini-agujero detectado en marzo de 2025 sobre el Observatorio Atmosférico de la Patagonia Austral (OAPA), Río Gallegos, Argentina (51,55° S, 69,23° O) y se evalúa su impacto radiativo en superficie. Se utilizaron observaciones satelitales del Tropospheric Monitoring Instrument (TROPOMI/Sentinel-5 Precursor) y Ozone Monitoring Instrument (OMI/NASA EOS-Aura), mediciones de superficie del espectrofotómetro Système d’Analyse par Observation Zénithale (SAOZ) y del radiómetro UVB-1 YES, y el producto de reanálisis Multi Sensor Reanalysis versión 2 (MSR-2). Se calcularon climatologías de largo plazo en el área de estudio con el fin de identificar eventos anómalos de la columna total de ozono (CTO) y cuantificar la respuesta del índice UV (IUV) y de la dosis eritémica diaria. La detección del evento se basó en un umbral climatológico (μ−2σ) y se complementó con simulaciones radiativas del IUV modeladas con un modelo paramétrico. Los resultados muestran una disminución simultánea de la CTO registrada por SAOZ (−16%) y TROPOMI (−19%) respecto del valor climatológico del día 24 de marzo 2025, alcanzando percentiles <1%. Esta reducción se tradujo en un incremento teórico de la dosis eritémica de +30% bajo condiciones despejadas respecto a la climatología para ese día, mientras que las observaciones reales indicaron un aumento más moderado (+9%), atribuible a la atenuación por nubosidad, dado que la tropósfera sobre el sitio tiene típicamente muy escaso contenido de aerosoles. Los mapas satelitales confirmaron la presencia y evolución espacial del mini-agujero sobre el sur de Sudamérica. Este estudio evidencia la utilidad del monitoreo integrado satélite–superficie para la detección de eventos extremos de ozono en latitudes subpolares. La metodología propuesta es transferible a otras regiones y contribuye al entendimiento de los riesgos asociados a episodios agudos de exposición a radiación UV.; The transient yet abrupt reduction of the ozone layer known as a “mini-ozone hole” can locally increase surface ultraviolet (UV) radiation, with potential implications for human health and ecosystems. In South America these phenomena have been sparsely documented, underscoring the need for detailed studies. Here we present the first characterization of a mini-ozone hole detected in March 2025 at the Observatorio Atmosférico de la Patagonia Austral (OAPA), Río Gallegos, Argentina (51.55° S, 69.23° W) and assess its surface radiative impact. We employed satellite observations Tropospheric Monitoring Instrument (TROPOMI/Sentinel-5 Precursor) and Ozone Monitoring Instrument (OMI/NASA EOS-Aura), ground-based measurements Système d’Analyse par Observation Zénithale spectrophotometer (SAOZ) and YES UVB-1 solar radiometer and a reanalysis product from Multi Sensor Reanalysis version 2 (MSR-2). Long-term climatologies for the study area were computed to identify anomalous total ozone column (TOC) events and to quantify the response of the UV index (UVI) and the daily erythemal dose. Event detection used a climatological threshold (μ−2σ) and was complemented by UVI radiative simulations generated with a parametric model. Results show a simultaneous decrease in TOC recorded by SAOZ (−16%) and TROPOMI (−19%) relative to the climatological value on 24 March 2025, reaching percentiles below 1%. This reduction corresponded to a theoretical increase in the erythemal dose of +30% under clear-sky conditions compared with the climatology for that day; observed values showed a more moderate rise (+9%), attributable to attenuation by clouds, given that the troposphere above the site has a very low aerosol content. Satellite maps confirmed the presence and spatial evolution of the mini-ozone hole over southern South America. This study demonstrates the value of integrated satellite–ground monitoring for detecting extreme ozone events at subpolar latitudes. The proposed methodology is transferable to other regions and contributes to improved understanding of the risks associated with acute UV exposure episodes. Fil: Laino-Baldini, Cristian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Hidrología de Llanuras Dr. Eduardo Jorge Usunoff; Argentina.; Fil: Carmona, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Hidrología de Llanuras Dr. Eduardo Jorge Usunoff; Argentina.; Fil: Wolfram, Elián. Servicio Meteorológico Nacional;  Argentina.; Fil: Carbajal-Benítez, Gerardo. Servicio Meteorológico Nacional;  Argentina.; Fil: Luccini, Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Facultad de Química e Ingeniería del Rosario. Pontificia Universidad Católica; Argentina.; Fil: Orte, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Departamento de Investigación en Láseres y Aplicaciones; Argentina.

Exploring Quantitative Observation Impact in Partial and Continuous Cycling Ensemble Kalman Filter Data Assimilation Systems

2025-05-01T07:50:39Z

Exploring Quantitative Observation Impact in Partial and Continuous Cycling Ensemble Kalman Filter Data Assimilation Systems Casaretto, Gimena; Schwartz, Craig S.; Dillon, María Eugenia; García Skabar, Yanina; Ruiz, Juan José This study applies the Ensemble Forecast Sensitivity to Observation Impact (EFSOI) technique to two 80-member ensemble Kalman filter (EnKF) data assimilation (DA) systems over the United States, differing only in cycling strategy: continuous cycling (CC) and partial cycling (PC). EFSOI calculations were performed using 1-hour, 6-hour and 12-hour evaluation forecast times, verified against the Rapid Refresh Model (RAP) analysis. Beneficial impact rates indicated that most observations were beneficial for both DA systems and forecast times, with no significant difference between PC and CC. Differences in cumulative observation impacts were statistically significant only for sources with few observations and small impacts, like mesonet observations. For numerous and impactful observations, such as rawinsondes and aircraft, differences were not statistically significant, suggesting similar use of important observations by PC and CC. PC forecasts were better than CC forecasts, but this improvement is not clearly due to better use of observations. Variable-wise analysis showed similar behavior between PC and CC for impact rates and cumulative impacts of U, V, T, RH, and surface zonal wind. Overall, there was no evidence that either PC or CC systematically used observations better, with mixed results across observation types and sources. Differences between PC and CC were typically small and not statistically significant for the most impactful observations and variables. Fundamental methodological differences between PC and CC did not significantly impact their ability to assimilate observations, the process of ingesting global fields likely responsible for improved PC forecasts relative to CC. Fil: Casaretto, Gimena. Servicio Meteorológico Nacional. Dirección Nacional de Ciencia e Innovación en Productos y Servicios. Dirección de Productos de Modelación Ambiental y de Sensores Remotos; Argentina.

Balancing Earth science careers in an unequal world

2025-02-20T11:52:03Z

Balancing Earth science careers in an unequal world Testani, Nadia; Cappelletti, Lucía M.; Díaz, Leandro B.; Prudente, Camila; Rabanal, Valentina; Mindlin, Julia; Börner, Reyk; Divya, David T.; Diallo, Ismaila; Leyba, Inés M.; Osman, Marisol; Tangarife-Escobar, Andrés Unequal research experiences among Earth scientists from around the world are an obstacle to achieving sustainability. In this comment, we assess challenges and propose ways to balance the careers of early- and mid-career researchers in the Global South with those in the Global North.; La inequidad en las experiencias de investigación entre los científicos de ciencias de la TIerra de todo el mundo es un obstáculo para alcanzar la sostenibilidad. En este trabajo, evaluamos los desafíos y proponemos formas de equilibrar las carreras de los investigadores del Sur Global con aquellos del Norte Global.

Dynamics, Monitoring, and Forecasting of Tephra in the Atmosphere

2025-02-20T11:39:07Z

Dynamics, Monitoring, and Forecasting of Tephra in the Atmosphere Pardini, F.; Barsotti, S.; Bonadonna, C.; de’ Michieli Vitturi, M.; Folch, A.; Mastin, L.; Osores, María Soledad; Prata, A. T. Explosive volcanic eruptions inject hot mixtures of solid particles (tephra) and gasses into theatmosphere. Entraining ambient air, these mixtures can form plumes rising tens of kilometers until they spreadlaterally, forming umbrella clouds. While the largest clasts tend to settle in proximity to the volcano, the smallestfragments, commonly referred to as ash (≤2 mm in diameter), can be transported over long distances, formingvolcanic clouds. Tephra plumes and clouds pose significant hazards to human society, affecting infrastructure,and human health through deposition on the ground or airborne suspension at low altitudes. Additionally,volcanic clouds are a threat to aviation, during both high‐risk actions such as take‐off and landing and atstandard cruising altitudes. The ability to monitor and forecast tephra plumes and clouds is fundamental tomitigate the hazard associated with explosive eruptions. To that end, various monitoring techniques, rangingfrom ground‐based instruments to sensors on‐board satellites, and forecasting strategies, based on runningnumerical models to track the position of volcanic clouds, are efficiently employed. However, some limitationsstill exist, mainly due to the high unpredictability and variability of explosive eruptions, as well as themultiphase and complex nature of volcanic plumes. In the next decades, advances in monitoring andcomputational capabilities are expected to address these limitations and significantly improve the mitigation ofthe risk associated with tephra plumes and clouds.