Search results for "Clima"

Publics "difficiles", enseignants en difficulté, que peut-on faire ?

2009

09061

2019

Abstract The long-term relationship between temperature and hydroclimate has remained uncertain due to the short length of instrumental measurements and inconsistent results from climate model simulations. This lack of understanding is particularly critical with regard to projected drought and flood risks. Here we assess warm-season co-variability patterns between temperature and hydroclimate over Europe back to 850 CE using instrumental measurements, tree-ring based reconstructions, and climate model simulations. We find that the temperature–hydroclimate relationship in both the instrumental and reconstructed data turns more positive at lower frequencies, but less so in model simulations, …

Data sets for energy rating of photovoltaic modules

2013

Abstract A proposal for generating standard climatic data sets for use in energy rating of photovoltaic (PV) modules is presented which will give a good comparability between different technologies. The current proposal of standard data sets consisting of “typical days” do not give realistic estimates of PV performance and thus is not sufficient as a rating standard. A dataset striking the balance between being significant for any location but does not consisting of too much data is required. A method to generate such a dataset is presented, meeting all the requirements of an international standard while being sufficiently accurate to differentiate between different devices of different man…

Meridional gradients of light absorbing carbon over northern Europe

2008

In situ measurements have been made in the upper troposphere of the properties of particles containing light absorbing carbon (LAC). These measurements, made in late November 2006 over northern Europe, show that the average LAC mass concentration varies between 1 and 5 ng m−3 over a latitude range 50° to 70°N, with maxima at 50° and 66°. The relative fraction of all particles larger than 0.1 µm that contain LAC decreases at higher latitudes. The derived extinction coefficient, which also increases with latitude, reaches a maximum of 1.4 Mm−1 at 66°. The air mass histories associated with the LAC were evaluated with back trajectory analysis using wind field analysis from the European Center …

Economic evaluation of introduction of poplar as biomass crop in Italy

2014

Abstract Lignocellulosic biomass production deriving from agro forest species, as well as poplar ( Populus spp.), has denoted an increase in last years in UE also thanks to a series of policies aimed at reducing emissions of greenhouse gases and promoting renewable sources. In Italy poplar represents the main agro forest species and it is cultivated according to two different methods: very Short Rotation Coppice (vSRC) and Short Rotation Coppice (SRC). The aim of this paper has been to evaluate the economic feasibility of poplar as energy crop in the southern Italy and specifically to consider its competitiveness with respect to conventional crops. In particular, an economic analysis in a r…

Managing Greenhouse Gas Emissions for Airport Inventories: An Overview

2011

For some years now, problems relating to gas emissions that affect climate and result from human activities have assumed a global dimension of large importance. The climate is, indeed, influenced by the concentrations of some pollutants in the atmosphere; these pollutants trap the long wave radiation emitted by the Earth and alter the energy balance, causing an accentuation of the natural greenhouse effect. In this view an inventory of greenhouse gases can become the benchmark against which to measure the achievement of quantitative targets set at the political level in the fight against climate change. Contrary to a general inventory of emissions related with air quality objectives and loc…

Selection bias was reduced by recontacting nonparticipants

2016

Objective One of the main goals of health examination surveys is to provide unbiased estimates of health indicators at the population level. We demonstrate how multiple imputation methods may help to reduce the selection bias if partial data on some nonparticipants are collected. Study Design and Setting In the FINRISK 2007 study, a population-based health study conducted in Finland, a random sample of 10,000 men and women aged 25–74 years were invited to participate. The study included a questionnaire data collection and a health examination. A total of 6,255 individuals participated in the study. Out of 3,745 nonparticipants, 473 returned a simplified questionnaire after a recontact. Both…

Soil erosion modelling: A bibliometric analysis.

2021

16 Pags.- 12 Figs.- 8 Tabls.

PROGETTO LIFE11 ENV IT 215 RESILFORMED - RESILIENZA AL CAMBIAMENTO CLIMATICO NELLE FORESTE MEDITERRANEE

2013

Le condizioni climatiche delle regioni mediterranee, caratterizzate da frequenti annate siccitose, contribuiscono all’indebolimento degli ecosistemi forestali. Come risultato le foreste riducono le loro capacità produttive e sono più soggette a fenomeni di degrado secondario. Inoltre i contesti economico-sociali possono acuire il degrado con la diffusione di uno scorretto uso della risorsa (tagli boschivi, pascolamento) e con la diffusione degli incendi boschivi. L’obiettivo generale del progetto è preservare i sistemi forestali in ambiente mediterraneo dai rischi derivanti dai cambiamenti climatici, tramite processi di naturalizzazione, aumento di biodiversità e migliorata reattività, nei …

Desalination. From a questioned resource to a necessary and strategic resource during drought situations for the water supply in the Segura River Bas…

2018

En España, la desalinización ha cobrado un gran impulso en las dos últimas décadas gracias a la aprobación en 2001 del Plan Hidrológico Nacional y en 2004 del Programa A.G.U.A. Ello ha sido motivado por dos factores principales: 1) Las recurrentes e intensas sequías en las últimas décadas, en especial, la de los años noventa en la que se puso de manifiesto la necesidad de la búsqueda de nuevas fuentes y la apuesta por los recursos hídricos no convencionales (desalinización y aguas regeneradas depuradas); y 2) Cambio del antiguo paradigma hidráulico basado en el incremento de la oferta mediante las transferencias de aguas. El objetivo de esta investigación es analizar el rol que ha desempeña…