13 research outputs found

    Spectral aerosol radiative forcing and efficiency of the La Palma volcanic plume over the Izaña Observatory

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    On 19 September 2021, a volcanic eruption began on the island of La Palma (Canary Islands, Spain). The eruption has allowed the assessment of an unprecedented multidisciplinary study on the effects of the volcanic plume. This work presents the estimation of the spectral direct radiative forcing (∆F) and efficiency (∆F E f f) from solar radiation measurements at the Izaña Observatory (IZO) located on the island of Tenerife (∼140 km from the volcano). During the eruption, the IZO was affected by different types of aerosols: volcanic, Saharan mineral dust, and a mixture of volcanic and dust aerosols. Three case studies were identified using ground based (lidar) data, satellite-based (Sentinel5P Tropospheric Monitoring Instrument, TROPOMI) data, reanalysis data (Modern-Era Retrospective Analysis for Research and Applications, version 2, MERRA-2), and backward trajectories (Flexible Trajectories, FLEXTRA), and subsequently characterised in terms of optical and micro-physical properties using ground based sun-photometry measurements. Despite the ∆F of the volcanic aerosols being greater than that of the dust events (associated with the larger aerosol load present), the ∆F E f f was found to be lower. The spectral ∆F E f f values at 440 nm ranged between −1.9 and −2.6 Wm−2nm−1AOD−1 for the mineral dust and mixed volcanic and dust particles, and between −1.6 and −3.3 Wm−2nm−1AOD−1 for the volcanic aerosols, considering solar zenith angles between 30◦ and 70◦, respectively.The authors also acknowledge the support of ACTRIS, Ministerio de Ciencia e Innovación of Spain, through the projects SYNERA: PID2020-118793GA-I00 and RT2018- 097864-B-I00, and Junta de Castilla y León grant N◦. VA227P20

    Medida del vapor de agua integrado en columna sobre el Observatorio Atmosférico de Izaña mediante radiometría de microondas. Comparación con otras técnicas

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    Se presentan en este estudio los resultados de la comparación entre las medidas del vapor de agua integrado en la columna total atmosférica (IWV), obtenido con un radiómetro de microondas RPG-LHATPRO de la serie G5 (MWR), en el Observatorio Atmosférico de Izaña (IZO) y los obtenidos mediante las técnicas FTIR, EKO MS-711, CIMEL, GNSS y radiosondas Väisala RS41 durante diferentes períodos de tiempo comprendidos entre mayo de 2020 y abril de 2023. Los resultados de la comparación indican una alta trazabilidad del MWR superior al 90% con la mayoría de las técnicas, siendo la técnica FTIR, con un 99%, la de mayor trazabilidad durante el día y las RS41, con un 98%, durante la noche. Como consecuencia, estas dos últimas técnicas podrían usarse en estudios que involucren medidas del IWV con el MWR en los que se necesiten complementar períodos de ausencias de datos para el día y la noche, respectivamente. El estudio nos ha permitido estimar también la exactitud y precisión de las medidas del IWV, así como el límite de detección de las diferentes técnicas, constatando que las técnicas MWR y CIMEL Lunar son las de mayor exactitud y precisión con límites de detección de 0.18 mm y 0.13 mm y máximas incertidumbres de 0.77 mm y 0.93 mm, respectivamente. Se constata también que el instrumento MWR mide más IWV que cualquiera de las otras técnicas, tanto de día como de noche (entre un 4% y un 22% más, dependiendo de la técnica). Asimismo, las diferencias entre el IWV del MWR y el del resto de técnicas muestran, en valor absoluto, un progresivo aumento lineal con el contenido de vapor de agua, tanto de día como de noche, una ligera disminución con el ángulo cenital solar y un muy débil aumento con el ángulo cenital lunar. El ángulo de fase lunar influye en la comparación disminuyendo las diferencias entre MWR y CIMEL Lunar en el rango [-30º, 30º]

    Aerosol characterisation in the subtropical eastern North Atlantic region using long-term AERONET measurements

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    A comprehensive characterisation of atmospheric aerosols in the subtropical eastern North Atlantic has been carried out using long-term ground-based Aerosol Robotic NETwork (AERONET) photometric observations over the period 2005–2020 from a unique network made up of four stations strategically located from sea level to 3555 m on the island of Tenerife. This site can be considered a sentinel for the passage of airmasses going to Europe from Africa, and therefore the aerosol characterisation performed here adds important information for analysing their evolution during their path toward Northern Europe. Two of these stations (Santa Cruz de Tenerife – SCO – at sea level and La Laguna – LLO – at 580 m a.s.l.) are located within the marine atmospheric boundary layer (MABL), and the other two (Izaña – IZO – at 2373 m a.s.l. and Teide Peak – TPO – at 3555 m a.s.l.) are high mountain stations within the free troposphere (FT). Monthly climatology of the aerosol optical depth (AOD), Ångström exponent (AE), aerosol concentration, size distribution and aerosol optical properties has been obtained for the MABL and FT. Measurements that are quite consistent across the four sites have been used to categorise the main atmospheric scenarios, and these measurements confirm an alternation between predominant background conditions and predominant dust-loaded Saharan air mass conditions caused by seasonal dust transport over the subtropical North Atlantic. Background conditions prevail in the MABL and FT for most of the year, while dust-laden conditions dominate in July and August.The authors also acknowledge the support from ACTRIS, Ministerio de Ciencia e Innovación, Spain, through the projects SYNERA (PID2020-118793GA-I00) and ePOLAAR (RTI2018-097864-BI00) and from Junta de Castilla y León (grant no. VA227P20)

    A new zenith-looking narrow-band radiometer-based system (ZEN) for dust aerosol optical depth monitoring

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    This study presents a new zenith looking narrow-band radiometer based system (ZEN), conceived for dust aerosol optical depth (AOD) monitoring. Our results suggest that ZEN is a suitable system to fill the current observational gaps and to complement observations performed by sun-photometer networks in order to improve mineral dust monitoring in remote locations.AERONET sun photometers at Izaña have been calibrated within the AERONET Europe TNA, supported by the European Community-Research Infrastructure Action under the FP7 15 ACTRIS grant agreement no. 262254

    Izaña Atmospheric Research Center. Activity Report 2019-2020

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    Editors: Emilio Cuevas, Celia Milford and Oksana Tarasova.[EN]The Izaña Atmospheric Research Center (IARC), which is part of the State Meteorological Agency of Spain (AEMET), is a site of excellence in atmospheric science. It manages four observatories in Tenerife including the high altitude Izaña Atmospheric Observatory. The Izaña Atmospheric Observatory was inaugurated in 1916 and since that date has carried out uninterrupted meteorological and climatological observations, contributing towards a unique 100-year record in 2016. This reports are a summary of the many activities at the Izaña Atmospheric Research Center to the broader community. The combination of operational activities, research and development in state-of-the-art measurement techniques, calibration and validation and international cooperation encompass the vision of WMO to provide world leadership in expertise and international cooperation in weather, climate, hydrology and related environmental issues.[ES]El Centro de Investigación Atmosférica de Izaña (CIAI), que forma parte de la Agencia Estatal de Meteorología de España (AEMET), representa un centro de excelencia en ciencias atmosféricas. Gestiona cuatro observatorios en Tenerife, incluido el Observatorio de Izaña de gran altitud, inaugurado en 1916 y que desde entonces ha realizado observaciones meteorológicas y climatológicas ininterrumpidas y se ha convertido en una estación centenaria de la OMM. Estos informes resumen las múltiples actividades llevadas a cabo por el Centro de Investigación Atmosférica de Izaña. El liderazgo del Centro en materia de investigación y desarrollo con respecto a las técnicas de medición, calibración y validación de última generación, así como la cooperación internacional, le han otorgado una reputación sobresaliente en lo que se refiere al tiempo, el clima, la hidrología y otros temas ambientales afines

    Izaña Atmospheric Research Center. Activity Report 2015-2016

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    This report is a summary of the many activities at the Izaña Atmospheric Research Center to the broader community. The combination of operational activities, research and development in state-of-the-art measurement techniques, calibration and validation and international cooperation encompass the vision of WMO to provide world leadership in expertise and international cooperation in weather, climate, hydrology and related environmental issues

    Clustering COVID-19 ARDS patients through the first days of ICU admission. An analysis of the CIBERESUCICOVID Cohort

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    Background Acute respiratory distress syndrome (ARDS) can be classified into sub-phenotypes according to different inflammatory/clinical status. Prognostic enrichment was achieved by grouping patients into hypoinflammatory or hyperinflammatory sub-phenotypes, even though the time of analysis may change the classification according to treatment response or disease evolution. We aimed to evaluate when patients can be clustered in more than 1 group, and how they may change the clustering of patients using data of baseline or day 3, and the prognosis of patients according to their evolution by changing or not the cluster.Methods Multicenter, observational prospective, and retrospective study of patients admitted due to ARDS related to COVID-19 infection in Spain. Patients were grouped according to a clustering mixed-type data algorithm (k-prototypes) using continuous and categorical readily available variables at baseline and day 3.Results Of 6205 patients, 3743 (60%) were included in the study. According to silhouette analysis, patients were grouped in two clusters. At baseline, 1402 (37%) patients were included in cluster 1 and 2341(63%) in cluster 2. On day 3, 1557(42%) patients were included in cluster 1 and 2086 (57%) in cluster 2. The patients included in cluster 2 were older and more frequently hypertensive and had a higher prevalence of shock, organ dysfunction, inflammatory biomarkers, and worst respiratory indexes at both time points. The 90-day mortality was higher in cluster 2 at both clustering processes (43.8% [n = 1025] versus 27.3% [n = 383] at baseline, and 49% [n = 1023] versus 20.6% [n = 321] on day 3). Four hundred and fifty-eight (33%) patients clustered in the first group were clustered in the second group on day 3. In contrast, 638 (27%) patients clustered in the second group were clustered in the first group on day 3.Conclusions During the first days, patients can be clustered into two groups and the process of clustering patients may change as they continue to evolve. This means that despite a vast majority of patients remaining in the same cluster, a minority reaching 33% of patients analyzed may be re-categorized into different clusters based on their progress. Such changes can significantly impact their prognosis
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