Search results for "sun"
showing 10 items of 935 documents
A glimpse of the limits of the European economic governance through the legislative and jurisprudential route of the "after-Weimar" German "economic …
2020
El objetivo de esta investigación es reconstruir los límites de la gestión de las finanzas públicas en la Unión Monetaria Europea, utilizando la perspectiva del camino de la "constitución económica" alemana posterior a Weimar. El proceso federativo de la UE no presenta las mismas características legales de ningún otro, incluido el alemán. Sin embargo, algunos problemas son necesariamente similares y similares soluciones se pueden encontrar. En consecuencia, esto documento se centra en la sucesión de reformas en la governance económica europea desde 2008 analizando, en particular, el tema de compartir las obligaciones de la deuda a nivel europeo, esto a través del diálogo entre el Bundesverf…
Airborne Measurements of Contrail Ice Properties—Dependence on Temperature and Humidity
2021
The largest share in the climate impact of aviation results from cirrus clouds. Here, the dependence of microphysical contrail ice properties and extinction on temperature and humidity is investigated. Contrail measurements were performed at various altitudes during the 2018 ECLIF II/NDMAX campaign with the NASA DC-8 chasing the DLR A320. Ice number concentrations and contrail extinction coefficients are largest at altitudes near 9.5 km, typical for short- and medium-range air traffic. At higher altitudes near 11.5 km, low ambient water vapor concentrations lead to smaller contrail particle sizes and lower extinction coefficients. In addition, contrails were detected below 8.2 km near the S…
Modelling of asymmetric nanojets in coronal loops
2021
Context. Observations of reconnection jets in the solar corona are emerging as a possible diagnostic for studying highly elusive coronal heating. Such jets, and in particular those termed nanojets, can be observed in coronal loops and have been linked to nanoflares. However, while models successfully describe the bilateral post-reconnection magnetic slingshot effect that leads to the jets, observations reveal that nanojets are unidirectional or highly asymmetric, with only the jet travelling inward with respect to the coronal loop’s curvature being clearly observed. Aims. The aim of this work is to address the role of the curvature of the coronal loop in the generation and evolution of asym…
LA FATTISPECIE PRESUNTIVA
2012
Remote sensing of sun-induced chlorophyll fluorescence at different scales
2014
In this contribution we present activities and selected results obtained in recent studies and campaigns conducted in the context of the FLuorescence EXplorer (FLEX) mission. FLEX is a candidate mission for the ESA 8th Earth Explorer and large efforts are currently dedicated to the development of an implementation scheme for an accurate mapping of fluorescence from the selected spaceborne sensor and mission configuration. Field and airborne data collected in different experimental campaigns, together with simulated data, have been used to demonstrate the feasibility of fluorescence retrievals and the potential of exploiting high spatial resolution fluorescence maps for a better understandin…
The Elliptic Sunrise
2020
In this talk, we discuss our recent computation of the two-loop sunrise integral with arbitrary non-zero particle masses in the vicinity of the equal mass point. In two space-time dimensions, we arrive at a result in terms of elliptic dilogarithms. Near four space-time dimensions, we obtain a result which furthermore involves elliptic generalizations of Clausen and Glaisher functions.
Spanish Stock Returns: Where is the Weather Effect?
2003
Psychological studies support the existence of an influence of weather on mood. Saunders (1993) and Hirshleifer and Shumway (2001) argue that the weather could affect the behaviour of market traders and, therefore, it should be reflected in the stock returns. This paper investigates the possible relation between weather and market index returns in the context of the Spanish market. In 1989, this market changed its open outcry trading system into a computerised and decentralised trading system. Therefore, it is possible to check the influence of weather variables (sunshine hours and humidity levels) on index returns in an open outcry trading system, and to compare it with a screen traded env…
Sun radiation and temperature impact at different periods of the year on the photooxidation of polyethylene films
2017
Analysis of the IR spectra of weathered films exposed at different periods of the year reveals that, the main regions of the IR spectrum affected by solar irradiation and temperature variation are the complex carbonyls and unsaturations composite absorption bands. Their respective kinetics vary in different manner according to the period at which the exposure is started. Curve fitting has been performed to refine the analysis of the IR spectra and to identify all the chemical species constituting the complex absorption bands. The analysis of the results let appears that whatever the exposure period of the year is, it does not affect the type of developing products, but it has strong effect …
Exploring the spatial relationship between airborne-derived red and far-red sun-induced fluorescence and process-based GPP estimates in a forest ecos…
2019
International audience; Terrestrial gross primary productivity (GPP) plays an essential role in the global carbon cycle, but the quantification of the spatial and temporal variations in photosynthesis is still largely uncertain. Our work aimed to investigate the potential of remote sensing to provide new insights into plant photosynthesis at a fine spatial resolution. This goal was achieved by exploiting high-resolution images acquired with the FLuorescence EXplorer (FLEX) airborne demonstrator HyPlant. The sensor was flown over a mixed forest, and the images collected were elaborated to obtain two independent indicators of plant photosynthesis. First, maps of sun-induced chlorophyll fluore…