Search results for "Climate"
showing 10 items of 4934 documents
A simple method for estimating downward longwave radiation from surface and satellite data by clear sky
1990
Abstract An attempt to derive downward longwave radiation at the surface in clear sky conditions is presented. A method that integrates satellite-measured infrared radiation temperatures with ground measurements of water vapour pressure is applied to Meteosat data. Satellite-derived fluxes are compared with corresponding ground-measured fluxes at three different sites in France and during various seasons. Comparison of the daily averaged fluxes shows a correlation coefficient of 0–88 and an r.m.s. difference between satellite estimates and ground measurements of 12 Wm-2.
The EuroSTARRS airborne campaign in support of the SMOS mission: first results over land surfaces
2004
A number of experiments using ground-based and airborne sensors have shown the high potential of L-band passive microwave radiometry for estimating and monitoring surface soil moisture. This has led to the Soil Moisture and Ocean Salinity (SMOS) mission, a European Space Agency (ESA) Earth Explorer Opportunity mission. SMOS has the objective to observe soil moisture over land and sea surface salinity over sea, both key parameters for atmospheric, oceanographic and hydrological predictive models. In preparation of SMOS, the EuroSTARRS airborne campaign was carried out in November 2001. Multi-angular measurements of the surface brightness temperature at L-band (1.4 GHz) at vertical polarizati…
An integrated modelling and remote sensing approach for hydrological study in arid and semi-arid regions: the SUDMED Program
2008
International audience; Recent efforts have been concentrated in the development of models to understand and predict the impact of environmental changes on hydrological cycle and water resources in arid and semi-arid regions. In this context, remote sensing data have been widely used to initialize, to force, or to control the simulations of these models. However, for several reasons, including the difficulty in establishing relationships between observational and model variables, the potential offered by satellite data has not been fully used. As a matter of fact, a few hydrological studies that use remote sensing data emanating from different sources (sensors, platforms) have been performe…
Quantification of land-atmosphere exchanges of water, energy and carbon dioxide in space and time over the heterogeneous Barrax site
2008
International audience; To advance our understanding of land-atmosphere exchanges of water, energy and carbon dioxide (CO2) in space and time over heterogeneous land surfaces, two intensive field campaigns were carried out at the Barrax agricultural test site in Spain during 12-21 July 2004 (SPARC 2004) and 8-14 July 2005 (SEN2FLEX 2005) involving multiple field, satellite and airborne instruments for characterizing the state of the atmosphere, the vegetation and the soil from the visible to the microwave range of the spectrum. Part of the experimental area is a core site of area 25 km2, within which numerous crops are grown, on both irrigated and dry land, alongside fields of bare soil. Th…
Switch in Relative Stability between cis and trans 2-Butene on Pt(111) as a Function of Experimental Conditions: A Density Functional Theory Study
2018
International audience; The adsorption of cis and trans 2-butenes on Pt(111) has been studied as a function of hydrogen coverage OH by means of calculations based on density functional theory (DFT) with the inclusion of dispersion forces. All hydrogen coverages have been considered, from 0 to 1.00 monolayer (ML). For each case, the di-sigma and pi adsorption geometries of the olefins have been compared at a surface coverage of theta(C4H8) = 0.11 ML. Calculations of the Gibbs free energies of these systems have identified the most stable 2-butene isomer (cis or trans) as a function of coverage, temperature, and pressure. In particular, focus was placed on two sets of conditions, namely, one …
Could the acid-base status of Antarctic sea urchins indicate a better-than-expected resilience to near-future ocean acidification?
2015
13 pages; International audience; Increasing atmospheric carbon dioxide concentration alters the chemistry of the oceans towards more acidic conditions. Polar oceans are particularly affected due to their low temperature, low carbonate content and mixing patterns, for instance upwellings. Calcifying organisms are expected to be highly impacted by the decrease in the oceans' pH and carbonate ions concentration. In particular, sea urchins, members of the phylum Echinodermata, are hypothesized to be at risk due to their high-magnesium calcite skeleton. However, tolerance to ocean acidification in metazoans is first linked to acid–base regulation capacities of the extracellular fluids. No infor…
Nouvelles données sur le genre Bragasellus (Crustacea: Isopoda: Asellidae
1996
From now on, the genus Bragasellus Henry & Magniez, 1968 includes 2 oculated and 17 stygobiotic species. As a natural and monophyletic taxonomic unit, we consider it a good genus. Its original area corresponds to the north-west quarter of the Iberian Peninsula. Secondarily, this area has extended eastward, using mainly the alluvial channels of hydrographic systems (Ríos Douro + Ebro and tributaries), finally reaching the underground waters of several Mediterranean rivers. This active expansion is exclusively due to the migration of two stygobiotic sibling species: B. lagari Henry & Magniez, 1973 towards the high basin of the Río Tajo, then downstream to the basins of the Ríos Jucar and Turi…
Runs of homozygosity in the Italian goat breeds: impact of management practices in low-input systems
2021
Abstract Background Climate and farming systems, several of which are considered as low-input agricultural systems, vary between goat populations from Northern and Southern Italy and have led to different management practices. These processes have impacted genome shaping in terms of inbreeding and regions under selection and resulted in differences between the northern and southern populations. Both inbreeding and signatures of selection can be pinpointed by the analysis of runs of homozygosity (ROH), which provides useful information to assist the management of this species in different rural areas. Results We analyzed the ROH distribution and inbreeding (FROH) in 902 goats from the Italia…
Sport commitment and adherence: A social-cognitive analysis. (Compromiso deportivo y adherencia: Un análisis cognitivo social).
2011
Abstract Statement of problem: This study aimed to analyse the ability of a model based on achievement motivation and self-determination theories to predict adherence to competitive sport. This model incorporated commitment as predictor of adherence. A prospective study was performed with a sample of 302 handball players aged between 14 and 18 years. Structural equation modelling gave support to the model proposed. It was verified the sequence of relationships between perceptions of coach-created mastery climate, psychological needs, self-determined motivation, commitment, and adherence. The major contribution of the study was to confirm a motivational model of adherence based on social-cog…
School climate as predictor of teachers’ capacity to meet the educational needs of adopted children in Italy
2020
The current study examines the association between different components of school climate (teacher–principal and teacher–parent relationships, parents’ involvement in school activities, connection between school and the local services) and teachers’ competences and knowledge regarding the adoption experience. Participants were 573 teachers (95.7% women; mean age = 47.06, SD = 8.66, ranging between 25 and 65) residing in three Italian regions characterised by rates of international adoptions that are higher than the national average. The association between school climate and teachers’ knowledge and competences on adoption was evaluated via independent multiple logistic regression analyses. …