18 research outputs found

    Circumsolar energetic particle distribution on 2011 November 3

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    Late on 2011 November 3, STEREO-A, STEREO-B, MESSENGER, and near-Earth spacecraft observed an energetic particle flux enhancement. Based on the analysis of in situ plasma and particle observations, their correlation with remote sensing observations, and an interplanetary transport model, we conclude that the particle increases observed at multiple locations had a common single source active region and the energetic particles filled a very broad region around the Sun. The active region was located at the solar backside (as seen from Earth) and was the source of a large flare, a fast and wide coronal mass ejection, and an EIT wave, accompanied by type II and type III radio-emission. In contrast to previous solar energetic particle events showing broad longitudinal spread, this event showed clear particle anisotropies at three widely separated observation points at 1AU, suggesting direct particle injection close to the magnetic footpoint of each spacecraft, lasting for several hours.We discuss these observations and the possible scenarios explaining the extremely broad particle spread for this event

    Application of Atmospheric Transport Models at the new atmospheric Ebre Delta station (ClimaDat network) in Eastern Spain

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    Abstract: The Ebre Delta atmospheric station (DEC3) was installed in Eastern Spain, within the framework of the ClimaDat project of the Institut Català de Ciències del Clima (IC3). This station offers continuous measurements of greenhouse gases and tracers concentrations (CO 2 , CH 4 , CO, N 2 O and SF 6 ), along with atmospheric concentrations of the natural radioactive gas 222 Rn. Meteorological parameters, such as humidity, temperature, wind speed and wind direction are also measured at DEC3 site. This qualitative analysis aims to use the FLEXPART and the HYSPLIT models, with meteorological input of ECMWF and with spatial resolution of 0.2 degrees, to perform back trajectories at DEC3 station and qualitatively analyze how different air masses coming from the Northern Western Europe or from the Mediterranean Sea influence observed gases concentrations

    Application of atmospheric transport models at the new atmospheric Ebre Delta station (ClimaDat Network) in Eastern Spain

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    The Ebre Delta atmospheric station (DEC3) was installed in Eastern Spain, within the framework of the ClimaDat project of the Institut Català de Ciències del Clima (IC3). This station offers continuous measurements of greenhouse gases and tracers concentrations (CO2, CH4, CO, N2O and SF6), along with atmospheric concentrations of the natural radioactive gas 222Rn. Meteorological parameters, such as humidity, temperature, wind speed and wind direction are also measured at DEC3 site. This qualitative analysis aims to use the FLEXPART and the HYSPLIT models, with meteorological input of ECMWF and with spatial resolution of 0.2 degrees, to perform back trajectories at DEC3 station and qualitatively analyze how different air masses coming from the Northern Western Europe or from the Mediterranean Sea influence observed gases concentrations.Postprint (published version

    Prospective individual patient data meta-analysis of two randomized trials on convalescent plasma for COVID-19 outpatients

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    Data on convalescent plasma (CP) treatment in COVID-19 outpatients are scarce. We aimed to assess whether CP administered during the first week of symptoms reduced the disease progression or risk of hospitalization of outpatients. Two multicenter, double-blind randomized trials (NCT04621123, NCT04589949) were merged with data pooling starting when = 50 years and symptomatic for <= 7days were included. The intervention consisted of 200-300mL of CP with a predefined minimum level of antibodies. Primary endpoints were a 5-point disease severity scale and a composite of hospitalization or death by 28 days. Amongst the 797 patients included, 390 received CP and 392 placebo; they had a median age of 58 years, 1 comorbidity, 5 days symptoms and 93% had negative IgG antibody-test. Seventy-four patients were hospitalized, 6 required mechanical ventilation and 3 died. The odds ratio (OR) of CP for improved disease severity scale was 0.936 (credible interval (CI) 0.667-1.311); OR for hospitalization or death was 0.919 (CI 0.592-1.416). CP effect on hospital admission or death was largest in patients with <= 5 days of symptoms (OR 0.658, 95%CI 0.394-1.085). CP did not decrease the time to full symptom resolution

    Study of the daily and seasonal atmospheric CH<sub>4</sub> mixing ratio variability in a rural Spanish region using <sup>222</sup>Rn tracer

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    The ClimaDat station at Gredos (GIC3) has been continuously measuring atmospheric (dry air) mixing ratios of carbon dioxide (CO2) and methane (CH4), as well as meteorological parameters, since November 2012. In this study we investigate the atmospheric variability of CH4 mixing ratios between 2013 and 2015 at GIC3 with the help of co-located observations of 222Rn concentrations, modelled 222Rn fluxes and modelled planetary boundary layer heights (PBLHs). Both daily and seasonal changes in atmospheric CH4 can be better understood with the help of atmospheric concentrations of 222Rn (and the corresponding fluxes). On a daily timescale, the variation in the PBLH is the main driver for 222Rn and CH4 variability while, on monthly timescales, their atmospheric variability seems to depend on emission changes. To understand (changing) CH4 emissions, nocturnal fluxes of CH4 were estimated using two methods: the radon tracer method (RTM) and a method based on the EDGARv4.2 bottom-up emission inventory, both using FLEXPARTv9.0.2 footprints. The mean value of RTM-based methane fluxes (FR_CH4) is 0.11 mg CH4 m−2 h−1 with a standard deviation of 0.09 or 0.29 mg CH4 m−2 h−1 with a standard deviation of 0.23 mg CH4 m−2 h−1 when using a rescaled 222Rn map (FR_CH4_rescale). For our observational period, the mean value of methane fluxes based on the bottom-up inventory (FE_CH4) is 0.33 mg CH4 m−2 h−1 with a standard deviation of 0.08 mg CH4 m−2 h−1. Monthly CH4 fluxes based on RTM (both FR_CH4 and FR_CH4_rescale) show a seasonality which is not observed for monthly FE_CH4 fluxes. During January–May, RTM-based CH4 fluxes present mean values 25 % lower than during June–December. This seasonal increase in methane fluxes calculated by RTM for the GIC3 area appears to coincide with the arrival of transhumant livestock at GIC3 in the second half of the year

    Application of atmospheric transport models at the new atmospheric Ebre Delta station (ClimaDat Network) in Eastern Spain

    No full text
    The Ebre Delta atmospheric station (DEC3) was installed in Eastern Spain, within the framework of the ClimaDat project of the Institut Català de Ciències del Clima (IC3). This station offers continuous measurements of greenhouse gases and tracers concentrations (CO2, CH4, CO, N2O and SF6), along with atmospheric concentrations of the natural radioactive gas 222Rn. Meteorological parameters, such as humidity, temperature, wind speed and wind direction are also measured at DEC3 site. This qualitative analysis aims to use the FLEXPART and the HYSPLIT models, with meteorological input of ECMWF and with spatial resolution of 0.2 degrees, to perform back trajectories at DEC3 station and qualitatively analyze how different air masses coming from the Northern Western Europe or from the Mediterranean Sea influence observed gases concentrations

    Fuzzy model for risk assessment of persistent organic pollutants in aquatic ecosystems

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    We developed a model for evaluating the environmental risk of persistent organic pollutants (POPs) to aquatic organisms. The model is based on fuzzy theory and uses information provided by international experts through a questionnaire. It has been tested in two case studies for a particular type of POPs: brominated flame retardants (BFRs). The first case study is related to the EU-funded AQUATERRA project, with sampling campaigns carried out in two Ebro tributaries in Spain (the Cinca and Vero Rivers). The second one, named the BROMACUA project, assessed different aquatic ecosystems in Chile (San Vicente Bay) and Colombia (Santa Marta Marsh). In both projects, the BFRs under study were polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD). However, the model can be extrapolated to other POPs and to different aquatic ecosystems to provide useful results for decision-makers. © 2013 Elsevier Ltd. All rights reserved.The authors are grateful for the participation of the 38 scientists who replied to the questionnaire. In addition, the authors would like to thank the Autonomous Government of Catalonia (project No. 2009SGR1118), the BBVA Foundation through the BROMACUA project (Evaluación del impacto ambiental de los retardantes de llama bromados en ecosistemas acuáticos de América Latina) and the European Union under the Global Change and Ecosystems (FP6) Water Cycle and Soil Related Aspects (AQUATERRA, Project number 505428).Peer Reviewe
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