Comparative analysis of extreme ultraviolet solar radiation proxies during minimum activity levels

Four extreme ultraviolet (EUV) solar radiation proxies (Magnesium II core-to-wing ratio (MgII), Lyman α flux (Fα), 10.7-cm solar radio flux (F10.7), and sunspot number (Rz)) were analyzed during the last four consecutive solar activity minima to investigate how they differ during minimum periods and how well they represent solar EUV radiation. Their variability within each minimum and between minima was compared by considering monthly means. A comparison was also made of their role in filtering the effect of solar activity from the critical frequency of the ionospheric F2 layer, foF2, which at mid to low latitudes depends mainly on EUV solar radiation. The last two solar cycles showed unusually low EUV radiation levels according to the four proxies. Regarding the connection between the EUV “true” variation and that of solar proxies, according to the foF2 filtering analysis, MgII and Fα behaved in a more stable and suitable way, whereas Rz and F10.7 could be overestimating EUV levels during the last two minima, implying they would both underestimate the inter-minima difference of EUV when compared with the first two minima

Spatial features of geomagnetic cutoff rigidity secular variation using analytical approaches

The secular variation spatial pattern of geomagnetic cutoff rigidity, Rc, is analyzed considering analytical expressions. Störmer analytic Rc equation in terms of geomagnetic latitude is used considering a pure dipolar field for the centered and eccentric dipole coordinates, together with a dipole-quadrupole superposition simplified equation. Linear Rc time trend for the period 1900-2020 in a 5° × 15° latitude-longitude grid is assessed in each case and a comparative analysis is made with trends based on trajectory based Rc estimations. Common features with some analytic approaches are the two patches of Rc positive and negative trends in the western hemisphere, even though maximum and minimum trend values are underestimated in all analytical cases. Global mean values are almost coincident, except for the dipole-quadrupole superposition case. The salient patches pattern may be due mainly to the dipole axis rotation, more than to its center displacement, its decreasing momentum or the increasing quadrupolar component role. Even though with the advent of better computational tools the trajectory based estimation would be a natural choice to analyze Rc variations, we still consider that an appropriately modified Störmer equation, with its natural advantages of its analytical form and extremely fast way of computation, is sufficient for many applications.Fil: Comedi, Emanuel S.. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología; ArgentinaFil: Elias, Ana Georgina. Universidad Nacional de Tucumán. Instituto de Física del Noroeste Argentino. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Física del Noroeste Argentino; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología; ArgentinaFil: Zossi, Bruno Santiago. Universidad Nacional de Tucumán. Instituto de Física del Noroeste Argentino. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Física del Noroeste Argentino; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología; Argentin

Relative contribution of genetic and environmental effects on non-sugar compounds of cane juice

The juice of the sugar cane is composed of sugars, water and insoluble substances referred to as non-sugar compounds. Both sugar and non-sugar compounds are important in the factory because they are responsible for adverse effects on the quality and recovery of sucrose. Increases in the ash and starch contents may affect sucroserecovery and crystallization, while low phosphate concentrations (<300 mg/kg) may cause clarification defects. On theother hand, anthocyanin and phenolic compounds affect juice color and the settling velocity. The relative contributions of genotypic, environmental and interaction effects on the total variability of these non-sugar compounds and theirgenetic correlations were assessed. Determinations associated with non-sugar compounds were performed on a set of 10 genotypes evaluated across six sites of the Sugarcane Breeding Program of Tucumán, Argentina. Starch, ash, phosphates,phenols and color of sugarcane juice were analyzed during the beginning of harvest season in three consecutive years. For each variable, a mixed linear model was adjusted in order to estimate variance components associated with genotypeeffects, environmental effects and their interaction on the total trait variability. Genetically determined correlations were assessed through biplot analysis. Ash, starch and juice colour were associated with the genotype effect with contributions of 58%, 52% and 43% of non-error variability, respectively. These three variables showed negative genetic correlationswith sucrose content. In the case of phosphate and phenolic compounds, the environment was the principal source of variation. Therefore, ash and starch contents and juice colour would be the main determinants associated with non-sugar compounds to be considered in the characterization of genotypes according to industrial quality.Fil: Ostengo, Santiago. Estación Experimental Agroindustrial Obispo Colombres; ArgentinaFil: Cuenya, María Inés. Estación Experimental Agroindustrial Obispo Colombres; ArgentinaFil: Zossi, S.. Estación Experimental Agroindustrial Obispo Colombres; ArgentinaFil: Balzarini, Monica Graciela. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigaciones Agropecuarias. Unidad de Fitopatologia y Modelizacion Agricola. Grupo Vinculado Catedra de Estadistica y Biometria de la Facultad de Ciencias Agropecuarias de la Universidad Nacional de Cordoba Al Ufyma | Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Unidad de Fitopatologia y Modelizacion Agricola. Grupo Vinculado Catedra de Estadistica y Biometria de la Facultad de Ciencias Agropecuarias de la Universidad Nacional de Cordoba Al Ufyma.; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias. Departamento de Desarrollo Rural. Area de Estadística y Biometría; Argentin

Review of Long-Term Trends in the Equatorial Ionosphere Due the Geomagnetic Field Secular Variations and Its Relevance to Space Weather

The Earth’s ionosphere presents long-term trends that have been of interest since a pioneering study in 1989 suggesting that greenhouse gases increasing due to anthropogenic activity will produce not only a troposphere global warming, but a cooling in the upper atmosphere as well. Since then, long-term changes in the upper atmosphere, and particularly in the ionosphere, have become a significant topic in global change studies with many results already published. There are also other ionospheric long-term change forcings of natural origin, such as the Earth’s magnetic field secular variation with very special characteristics at equatorial and low latitudes. The ionosphere, as a part of the space weather environment, plays a crucial role to the point that it could certainly be said that space weather cannot be understood without reference to it. In this work, theoretical and experimental results on equatorial and low-latitude ionospheric trends linked to the geomagnetic field secular variation are reviewed and analyzed. Controversies and gaps in existing knowledge are identified together with important areas for future study. These trends, although weak when compared to other ionospheric variations, are steady and may become significant in the future and important even now for long-term space weather forecasts

Species diversification – which species should we use?

Large detector systems for particle and astroparticle physics; Particle tracking detectors; Gaseous detectors; Calorimeters; Cherenkov detectors; Particle identification methods; Photon detectors for UV. visible and IR photons; Detector alignment and calibration methods; Detector cooling and thermo-stabilization; Detector design and construction technologies and materials. The LHCb experiment is dedicated to precision measurements of CP violation and rare decays of B hadrons at the Large Hadron Collider (LHC) at CERN (Geneva). The initial configuration and expected performance of the detector and associated systems. as established by test beam measurements and simulation studies. is described. © 2008 IOP Publishing Ltd and SISSA