http://hdl.handle.net/20.500.11765/14266 2026-06-10T04:00:37Z http://hdl.handle.net/20.500.11765/17825 Título : Global Model Estimates of Atmospheric Al, Ca, Fe, Si, and Ti From Dust and Non-Dust Aerosols Informed by EMIT Surface Mineralogy and Evaluated Against Observations Autor : Mahowald, Natalie M.; Li, Longlei; Ageitos, María Gonçalves; Miller, Ron L.; Pérez García-Pando, Carlos; Ginoux, Paul; Obiso, Vincenzo; Brodrick, Philip G.; Clark, Roger N.; Desboeufs, Karine; Green, Robert O.; Okin, Gregory S.; Thompson, David R.; Rathod, Sagar D.; Gazel, Esteban; Hornby, Adrian; Journet, Emile; Alaimo, Maria Grazia; Alves, Célia; Alastuey, Andrés; Artaxo, Paulo; Baker, Alex R.; Barraza, Francisco; Becagli, Silvia; Buckley, Bruce; Buck, Clifton S.; Calzolai, Giulia; Chellam, Shankararaman; Chen, Ying; Chuang, Patrick Y.; Cohen, David D.; Colombi, Cristina; Diapouli, Evangelia; Dongarra, Gaetano; Eleftheriadis, Konstantinos; Engelbrecht, Johann P.; Galy-Lacaux, Corinne; Gaston, Cassandra J.; Gómez, Darío; González Ramos, Yenny; Hand, Jenny L.; Harrison, Roy M.; Herut, Barak; Hopke, Philip K.; Kertesz, Zsofia; Kyllönen, Katriina; Lambert, Fabrice; Landing, Willam M.; Losno, Remi; Lucarelli, Franco; Maenhaut, Willy; Marsay, Christopher; Matsui, Hitoshi; Martin, Randall V.; Morera-Gómez, Yasser; Paytan, Adina; Prospero, Joseph M.; Rodríguez González, Sergio; Sarthou, Geraldine; Shelley, Rachel; Siefert, Ronald L.; Smichowski, Patricia; Varrica, Daniela Resumen : Atmospheric deposition of micro-nutrients like Fe has been shown to be important for ocean biogeochemistry. The largest source of atmospheric Fe and other elements (e.g., Ca, Al, Si, and Ti) is desert dust, although there are significant non-dust sources in some regions (e.g., combustion, sea salts, volcanoes). However, past estimates of these elements have been substantially uncertain due to limited information about the composition of the desert source regions. Here we use elemental distributions estimated from new Earth Surface Mineral Dust Source Investigation (EMIT) observations, which provide mineralogical composition at the surface of the Earth based on imaging spectroscopy measurements from the International Space Station. We focus on total elemental amounts, not on the soluble fraction. We add in other sources of these elements (anthropogenic and natural) and compare to a compilation of available surface concentration data from stations over land and from shipborne observations. The combined observational and model synthesis provides new information about the distribution and deposition of these elements. Our results suggest that the modeled distribution is similar to available observations, but discrepancies still exist in both natural desert dust regions as well as regions dominated by anthropogenic sources. Comparisons between the model estimated Ca/Al ratios and observations in some dust dominated regions suggest an underestimate of Ca/Al ratios. Global budgets for Ca, Al, Fe, Si, and Ti suggest that desert dust remains the dominant source, although volcanic and anthropogenic contributions are important in some regions. Changes in elemental distributions since preindustrial times were also estimated. 2026-01-01T00:00:00Z http://hdl.handle.net/20.500.11765/17804 Título : Levante and Poniente winds in the Strait of Gibraltar: Present and future characterization using regional climate models Autor : Ortega Camacho, María; Gutiérrez, Claudia; López de la Franca, Noelia; Molina Sánchez, María Ofelia; Cabos, William; Sein, Dmitry; Sánchez, Enrique Resumen : Levante and Poniente are regional winds that appear in the Strait of Gibraltar with great intensity and frequency. However, they have not been the focus of many modelling studies so far. For this reason, the present work has two aims. First, to evaluate the capability to describe both winds using the largest available set of outputs from regional climate models and different wind data frequencies, spatial resolutions and atmosphere-ocean coupling characteristics. Second, to study wind changes between present (1950–2005) and future climate conditions (RCP8.5, 2006-2099). Results indicate that available spatial resolution is essential for a proper wind description. Internal physics are also a source of variation. Coupling effect does not lead to important changes on any of the studied regional winds. Levante occurs in the historical period between 110–130 days per year, covering 42%–44% of the Strait, with future increase of 10–20 annual events, depending on the model. Levante spatial extension varies with mixed trend signs. Poniente is detected between 135–155 days per year over 45%–50% of the Strait for the historical period and shows future debilitation in its magnitude with around 5–20 less days. This pioneering work manifests the capability of regional climate models to quantify Levante and Poniente events. Future climate change projections should be further studied to obtain as much regional climate model outputs as possible and to increase the robustness of such projections. Besides, a deeper analysis of weather variability patterns related to these wind conditions would strongly increase our understanding of the atmospheric mechanisms behind such important regional winds. 2026-01-01T00:00:00Z http://hdl.handle.net/20.500.11765/17793 Título : Impact of spectral aerosol radiative forcing at the Izaña observatory during the August 2023 extreme wildfires Autor : García Cabrera, Rosa Delia; Barreto Velasco, África; Cachorro, Victoria E.; González-Sicilia, Pablo; León-Luis, Sergio Fabián; Álvarez Hernández, Ayoze; Bustos Seguela, Juan José de; Ramos López, Ramón; Almansa Rodríguez, Antonio Fernando; Álvarez-Losada, Óscar; González Ramos, Yenny; Rivas Soriano, Pedro Pablo; Torres, Carlos Resumen : Extreme wildfires represent a highly variable source of atmospheric aerosols with potentially strong impacts on surface solar radiation. In August 2023, an exceptional wildfire on Tenerife (Canary Islands, Spain) reached the neighbourhoods of the Izaña Observatory (IZO, 2400 m a.s.l.). This near-source configuration enabled a rare observational characterisation of the spectral radiative effects of biomass-burning aerosols. During the most intense phases of the event (17–18 August), aerosol optical depth (AOD) at 500 nm reached extreme values of 3.63 and 2.25, respectively, with Ångström Exponent (AE) above 2, indicating a strong dominance of fine-mode smoke particles. Spectral measurements of global-horizontal, direct-normal and diffuse-horizontal solar irradiance (300–1100 nm) show a pronounced attenuation of direct and global irradiances, particularly in the visible range, together with a strong enhancement of diffuse radiation. Relative to clean-sky conditions, daily global irradiance decreased by 21 %–27 %, while direct-normal irradiance was reduced by 72 %–99 %. Spectral aerosol radiative forcing and radiative forcing efficiency at the surface were quantified using radiative transfer simulations under pristine atmospheric conditions as a reference. The integrated spectral radiative forcing (300–1100 nm) for global irradiance reached −395 and −299 W m−2 on 17 and 18 August, respectively, indicating strong surface cooling dominated by scattering processes. Maximum forcing and efficiency occurred in the visible spectral range, consistent with the optical properties of freshly emitted smoke aerosols. At the same time, increases in the amount of present particles, equivalent black carbon (eBC) and greenhouse gases (CO2, CH4 and CO) confirm the direct influence of the wildfire plume on atmospheric composition at IZO. These observations provide one of the few detailed spectral assessments of surface radiative forcing by extreme biomass-burning aerosols at a high-altitude site and highlight the need to accurately represent fine-mode smoke aerosols in radiative transfer and climate models. 2026-01-01T00:00:00Z 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. 2026-01-01T00:00:00Z