7,390 research outputs found

    BQC: A free web service to quality control solar irradiance measurements across Europe

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    Classical quality control (QC) methods of solar irradiance apply easy-to-implement physical or statistical limits that are incapable of detecting low-magnitude measuring errors due to the large width of the intervals. We previously presented the bias-based quality control (BQC), a novel method that flags samples in which the bias of several independent gridded datasets is larger for consecutive days than the historical value. The BQC was previously validated at 313 European and 732 Spanish stations finding multiple low-magnitude errors (e.g., shadows, soiling) not detected by classical QC methods. However, the need for gridded datasets, and ground measurements to characterize the bias, was hindering the BQC implementation. To solve this issue, we present a free web service, www.bqcmethod.com, that implements the BQC algorithm incorporating both the gridded datasets and the reference stations required to use the BQC across Europe from 1983 to 2018. Users only have to upload a CSV file with the global horizontal irradiance measurements to be analyzed. Compared to previous BQC versions, gridded products have been upgraded to SARAH-2, CLARA-A2, ERA5, and the spatial coverage has been extended to all of Europe. The web service provides a flexible environment that allows users to tune the BQC parameters and upload ancillary rain data that help in finding the causes of the errors. Besides, the outputs cover not only the visual and numerical QC flags but also daily and hourly estimations from the gridded datasets, facilitating the access to raster data.We thank the Instituto de Estudios Riojanos for funding part of the web service within the program Estudios Científicos de Temática Riojana, Spain. This research used resources from the Supercomputing Castilla y Leon Center (SCAYLE, www.scayle.es), funded by the European Regional Development Fund (ERDF). We would also like to thank the EU meteorological networks that freely distribute their datasets and particularly those researchers who helped us in retrieving these data: Aku Riiëla and Anders Lindfors (FMI), Virginie Gorjoux (Météo France), Sandra Andersson (SHMI), and Jakub Walawender (IMGW-PIB). Finally, we thank the CMSAF and ECMWF for freely distributing their products, and particularly Jörg Trentmann, for providing a beta version of CLARA-A2.1. RU is a postdoc from the University of La Rioja working as a visiting scientist at the European Commission’s Joint Research Center (JRC). RU is funded by the Plan Propio de la Universidad de La Rioja, Spain and V Plan Riojano de I+D, Spain . The views expressed here are purely those of the authors and may not, under any circumstances, be regarded as an official position of the European Commission

    Comparison of nitrification inhibitors to restrict nitrate leaching in a maize crop irrigated under mediterranean conditions

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    The aim of this paper was to compare dicyandiamide (DCD) and 3,4 dimethylpyrazole phosphate (DMPP) as inhibitors of ammonium oxidation and nitrate leaching after applying fertilizer to a maize (Zea mays L.) crop grown under Mediterranean conditions. The effects of nitrification inhibitors were also compared to those of N fertilization without inhibitors and with split N application. In plots fertilized with ammonium sulphate nitrate (ASN), either DCD or DMPP lengthened ammonium presence in soil and produced lower soil NO3- concentrations (30% lower than in plots with no inhibitor). The use of DCD or DMPP achieved significant reductions in nitrate leaching. DCD showed excellent properties for controlling nitrate leaching, taking into account the fact that grain yield and N accumulated by plant were similar for the ASN-DCD and ASN treatments applied at the same N doses. The split N treatment did not offer any advantages in terms of leached nitrate, either with the use of single ammonium sulphate nitrate (ASN) or with single application of nitrification inhibitors. The nitrification inhibitors did not increase the yield but did not reduce it either. The drainage rate was the most important component of nitrate leaching. The low drainage values of the first year resulted in a sharp decline of nitrate leaching. However, the experiment of the second year, showed clear differences in nitrate leaching between treatments due to the greater drainage

    Production of vector resonances at the LHC via WZ-scattering: a unitarized EChL analysis

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    In the present work we study the production of vector resonances at the LHC by means of the vector boson scattering WZWZWZ \to WZ and explore the sensitivities to these resonances for the expected future LHC luminosities. We are assuming that these vector resonances are generated dynamically from the self interactions of the longitudinal gauge bosons, WLW_L and ZLZ_L, and work under the framework of the electroweak chiral Lagrangian to describe in a model independent way the supposedly strong dynamics of these modes. The properties of the vector resonances, mass, width and couplings to the WW and ZZ gauge bosons are derived from the inverse amplitude method approach. We implement all these features into a single model, the IAM-MC, adapted for MonteCarlo, built in a Lagrangian language in terms of the electroweak chiral Lagrangian and a chiral Lagrangian for the vector resonances, which mimics the resonant behavior of the IAM and provides unitary amplitudes. The model has been implemented in MadGraph, allowing us to perform a realistic study of the signal versus background events at the LHC. In particular, we have focused our study on the ppWZjjpp\to WZjj type of events, discussing first on the potential of the hadronic and semileptonic channels of the final WZWZ, and next exploring in more detail the clearest signals. These are provided by the leptonic decays of the gauge bosons, leading to a final state with 1+12+νjj\ell_1^+\ell_1^-\ell_2^+\nu jj, =e,μ\ell=e,\mu, having a very distinctive signature, and showing clearly the emergence of the resonances with masses in the range of 1.5-2.5 TeV, which we have explored.Comment: Revised version accepted for publication in JHEP. Enlarged analysis. References added. 44 pages, 23 figures, 3 table
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