http://hdl.handle.net/20.500.11765/14266 Fri, 01 May 2026 17:21:31 GMT 2026-05-01T17:21:31Z http://hdl.handle.net/20.500.11765/17664 Título : Disentangling the drivers of soil CO2 ventilation in a Mediterranean dryland using in situ and remote sensing techniques Autor : Abril Gago, Jesús; Tovar, Irene; Echeverría, María Teresa; Andújar Maqueda, Juana; Ortiz Amezcua, Pablo; Cabrera Carrillo, Germán; Serrano Ortiz, Penélope; Domingo, Francisco; Alados Arboledas, Lucas; Kowalski, Andrew S.; Sánchez Cañete, Enrique P.; Guerrero-Rascado, Juan Luis Resumen : Subterranean CO2 concentrations are driven by complex interactions between biological and physical processes. In semiarid ecosystems, atmospheric processes can play a relevant role in modulating soil CO2 storage and release. In the current study, a multi-instrumental dataset, collected in a Mediterranean shrubland in southern Spain, was analyzed, and the main atmospheric drivers controlling soil CO2 and radon (Rn) dynamics were investigated. Based on a precise methodology, 10 significant ventilation events were detected, and the Spearman correlation coefficients between the soil CO2 and Rn concentrations and the different atmospheric variables were calculated. The results identified surface atmospheric pressure as the most consistent and independent driver across the events, exhibiting strong negative correlations with the subterranean CO2 and Rn concentrations. Surface-level friction velocity (u∗), boundary-layer turbulent kinetic energy dissipation rate (ϵ) and wind shear (sh) showed significant positive correlations. However, their independence was not consistent when compared with diluting ventilation events, when u∗ was more relevant, with enriching ventilation periods, that were more influenced by boundary-layer ϵ and sh. In contrast, at lower altitudes ϵ, sh, atmospheric boundary layer height and mixing layer height were less strongly correlated with soil CO2 and Rn concentration changes. These findings provide new insights into the mechanisms that promote soil-atmosphere transport in drylands, especially those regarding the carbon cycle, and highlight the need to incorporate such mechanisms into Earth system models to improve carbon cycle predictions under future climate scenarios. Thu, 01 Jan 2026 00:00:00 GMT http://hdl.handle.net/20.500.11765/17664 2026-01-01T00:00:00Z http://hdl.handle.net/20.500.11765/17663 Título : Volcanic plume height during the 2021 Tajogaite eruption (La Palma) from two complementary monitoring methods – implications for satellite-based products Autor : Barreto Velasco, África; Quirós, Francisco; García Rodríguez, Omaira Elena; Pereda de Pablo, Jorge; González-Fernández, Daniel; Bedoya Velásquez, Andrés Esteban; Sicard, Michaël; Córdoba-Jabonero, Carmen; Iarlori, Marco; Rizi, Vicenzo; Krotkov, Nickolay; Carn, Simon; Roininen, Reijo; Molina Arias, Antonio J.; Almansa Rodríguez, Antonio Fernando; Álvarez-Losada, Óscar; Aramo, Carla; Bustos Seguela, Juan José de; Ceolato, Romain; Comerón, Adolfo; Felpeto, Alicia; García Cabrera, Rosa Delia; González-Sicilia, Pablo; González Ramos, Yenny; Hedelt, Pascal; Hernández Martínez de la Peña, Miguel; López Cayuela, María Ángeles; Loyola, Diego; Meletlidis, Stavros; Muñoz Porcar, Constantino; Pietropaolo, Ermanno; Ramos López, Ramón; Rodríguez Gómez, Alejandro; Román, Roberto; Romero Campos, Pedro Miguel; Stuefer, Martin; Toledano, Carlos; Welton, Ellsworth J. Resumen : Volcanic emissions from the Tajogaite volcano, located on the Cumbre Vieja edifice on the island of La Palma (Canary Islands, Spain), caused significant public health and aviation disruptions throughout the eruption (19 September–13 December 2021, officially declared over on 25 December). Nonetheless, it is considered the most significant volcanic event in Europe over the past 75 years due to the substantial amount of SO2 released into the atmosphere. The Instituto Geográfico Nacional (IGN), the authority responsible for volcano surveillance in Spain, implemented extensive operational monitoring to track volcanic activity and to provide a robust estimation of the volcanic plume height using a video-surveillance network. In parallel, the State Meteorological Agency of Spain (AEMET), in partnership with other Spanish ACTRIS (Aerosol, Clouds, and Trace Gases Research Infrastructure) members and collaborating institutions, conducted an unprecedented instrumental deployment to evaluate the impacts of this volcanic event on atmospheric composition. This effort included a network of aerosol profilers surrounding the volcano. A total of four profiling instruments were installed on La Palma: one MPL-4B lidar and three ceilometers. Additionally, a pre-existing Raman lidar on the island contributed valuable data to this study. These efforts are undertaken due to the importance of monitoring volcanic plume height in terms of air quality (necessary for the implementation of effective civil protection policies), volcanic activity surveillance (for tracking and forecasting eruptive behaviour), and, from a scientific perspective, for improving our understanding of the climatic and radiative impacts of this type of aerosol. Thu, 01 Jan 2026 00:00:00 GMT http://hdl.handle.net/20.500.11765/17663 2026-01-01T00:00:00Z http://hdl.handle.net/20.500.11765/17634 Título : Exploring the Relationship Between Groundwater Drought and Evapotranspiration With the JULES Land Surface Model in a UK Chalk Catchment Autor : Collins, Sarah L.; Martínez de la Torre, Alberto; Scheidegger, Johanna; Clark, Douglas B.; Hughes, Andrew Resumen : Hydrological droughts can last months to years and impact large areas, leading to a multitude of ecological and socio-economicharm. The role of evapotranspiration (ET) in drought is very variable and there is contradicting evidence on the impact of anthro-pogenic warming on groundwater drought in the UK. We integrated a distributed groundwater model into the JULES land sur-face model (JULES-DGW) and simulated a chalk catchment in southern England over the period 1901–2015. The model showeda good match to river flows (Kling–Gupta efficiencies 0.73–0.83) and groundwater levels (r2 = 0.92). We found a general trendof drying over time with small decreases in average moisture in the unsaturated zone and average groundwater levels, causedby increases in annual ET and decreases in recharge as a fraction of precipitation. The model suggests drier conditions in theunsaturated zone in late summer/early autumn in the late 20th–early 21st century have led to a delay in the recharge season. Noincrease in capillary rise was simulated throughout the modelling period and ET was found to decrease in most cases of severedrought, thus acting to limit the fall in groundwater levels.1 | IntroductionHydrological droughts can last months to years and impact largeareas, leading to a multitude of ecological and socio-economicharms, including to water supply, crop production, river navi-gation and electricity production (Van Loon 2015). Climatechange accelerates the terrestrial water cycle, as warming drivesan increase in evapotranspiration (ET), causing more precipi-tation (J. Liu et al. 2013; Scheff and Frierson 2014). Increasesin ET have caused an intensification of the dry season acrosslarge parts of the globe (Padrón et al. 2020), bringing more fre-quent and intense ecological and agricultural droughts since the1950s, although there is little agreement regarding changes innorthern Europe (IPCC 2023). In the near future, analyses indi-cate reducing low flows and increasing duration and severity ofhydrological drought for much of the globe (e.g., Hari et al. 2020;C. Zhao et al. 2020; Spinoni et al. 2021; Gu et al. 2023).Groundwater is the Earth's largest liquid store of freshwater. Itplays a fundamental role in public water supply, irrigation andterrestrial ecosystems (Gleeson et al. 2012), sustaining base-flow to rivers, lakes and wetlands in periods of low rainfall.Groundwater comprises ~25% of all freshwater withdrawals(UN 2022) with an estimated 2.5 billion people solely dependenton its use (UNESCO 2015). Within the world's cities, groundwa-ter use is intensifying, with just under 50% of the global urbanpopulation dependent on groundwater (Foster et al. 2020).Groundwater systems are inherently more resilient to climatevariability, storing water from periods of surplus and, largely,protected from the evaporative losses suffered by reservoirs.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium,provided the original work is properly cited.© 2026 British Geological Survey © UKRI. Hydrological Processes published by John Wiley & Sons Ltd. Thu, 01 Jan 2026 00:00:00 GMT http://hdl.handle.net/20.500.11765/17634 2026-01-01T00:00:00Z http://hdl.handle.net/20.500.11765/17492 Título : Dynamic forcing behind Hurricane Lidia's rapid intensification Autor : López Reyes, Mauricio; Martín, María Luisa; Calvo Sancho, Carlos; González-Alemán, Juan Jesús Resumen : This study examines Hurricane Lidia's rapid intensification (RI) in the understudied northeastern Pacific, focusing on its interaction with an upper-level trough. Using IFS-ECMWF ensemble forecasts and ERA5 reanalysis, we analyze the large-scale dynamical mechanisms driving Lidia's intensification. Results show that the trough played a crucial role in promoting RI by enhancing synoptic-scale ascent, upper-level divergence, and eddy flux convergence. In the higher-intensification ensemble group, a coherent sequence emerged in which enhanced negative Trenberth forcing appeared several hours before RI onset, followed by marked increases in upper-level divergence, cyclonic vorticity advection, and mid-tropospheric moistening. These signals collectively reduced vertical wind shear over the storm and strengthened the upper-level outflow, creating an environment highly conducive to RI. In contrast, the lower-intensification group exhibited weaker forcing, higher shear, and a lack of sustained divergence in upper levels. These findings highlight the importance of diagnosing early dynamical triggers for RI, particularly in regions where operational access to high-resolution models is limited. A conceptual schematic synthesizes these multi-stage processes, highlighting how upper-level dynamical forcing and favorable thermodynamic conditions acted jointly to precondition and then accelerate RI. This approach provides a cost-effective framework for anticipating RI using ensemble-based diagnostics and could serve as a valuable forecasting tool in data-sparse areas such as the Pacific coast of Mexico. Future studies should combine this large-scale methodology with high-resolution simulations to better capture storm-scale processes and validate multi-scale interactions in RI events. Thu, 01 Jan 2026 00:00:00 GMT http://hdl.handle.net/20.500.11765/17492 2026-01-01T00:00:00Z