Search results for "ENERGY BALANCE"

Understanding the Effects of Fires on Surface Evapotranspiration Patterns Using Satellite Remote Sensing in Combination with an Energy Balance Model

2011

Forest fires are highly destructive for nature, affecting the landscape, the natural cicle of the vegetation, and the structure and functioning of ecosystems. Beyond that, they also provoke changes in the local and regional meteorology, and particularly in the surface energy flux patterns. In a fire-affected area, changes in the ecosystem structure and species composition modify the evapotranspiration (LE) and the rest of the terms involved in the energy balance equation. Besides, these changes in the local energy balance may persist for decades (Randerson et al., 2006). There is an increasing concern among the scientific community about the effect of forest fires on climate change at this …

Energy balance related behaviour: Personal, home- and friend-related factors among schoolchildren in Europe studied in the ENERGY-project

2014

Published version of an article in the journal: PLoS One. Also available from the publisher: http://dx.doi.org/10.1371/journal.pone.0111775 Open Acces Objective: To design interventions that target energy balance-related behaviours, knowledge of primary schoolchildren’s perceptions regarding soft drink intake, fruit juice intake, breakfast consumption, TV viewing and physical activity (PA) is essential. The current study describes personal beliefs and attitudes, home- and friend-related variables regarding these behaviours across Europe. Design: Cross-sectional study in which personal, family and friend -related variables were assessed by validated questionnaires, and dichotomized as favour…

Test-retest reliability and construct validity of the ENERGY-child questionnaire on energy balance-related behaviours and their potential determinant…

2011

Published version of an article in the journal: International Journal of Behavioral Nutrition and Physical Activity. Also available from the publihser:http://dx.doi.org/10.1186/1479-5868-8-136 BACKGROUND:Insight in children's energy balance-related behaviours (EBRBs) and their determinants is important to inform obesity prevention research. Therefore, reliable and valid tools to measure these variables in large-scale population research are needed.OBJECTIVE:To examine the test-retest reliability and construct validity of the child questionnaire used in the ENERGY-project, measuring EBRBs and their potential determinants among 10-12 year old children.METHODS:We collected data among 10-12 yea…

A link between the residual-based gradient plasticity theory and the analogous theories based on the virtual work principle

2009

A link is shown to exist between the so-called residual-based strain gradient plasticity theory and the analogous theories based on the (extended) virtual work principle (VWP). To this aim, the former theory is reformulated and cast in a residual-free form, whereby the insulation condition and the (nonlocal) Clausius–Duhem inequality, on which the theory is grounded, are substituted with equivalent residual-free ingredients, namely the energy balance condition and the residual-free form of the Clausius–Duhem inequality. The equivalence of the residual-free formulation to the original one is shown, also in their ability to cope with energetic size effects and interfacial energy ones. It emer…

A Possible Approach to Take into Account the Presence of Green Roofs in the Energy Certification of Buildings

2011

Uncertainties in The S-Sebi Model to Estimate Surface Energy Fluxes Over Natural Grasslands in Brazil

2021

Evapotranspiration (ET) is one of the main fluxes in the global water cycle. In this context, we assessed an operational methodology based on the S-SEBI model to accurately estimate energy fluxes over the natural grasslands of Pampa biome. The S-SEBI performance was investigated considering radiation data from both ERA5 reanalysis and tower flux. Comparisons from satellite-based estimates with in situ measurements were performed with and without energy balance closure (EBC). Results indicated that meteorological inputs have low sensitivity on daily ET estimates. In contrast, the instantaneous components are more affected. The impact in the daily ET is lower when in situ data without EBC are…

Crop Coefficient Curve for Paddy Rice from Residual Energy Balance Calculations

2017

AbstractThe crop coefficient (Kc) values of rice paddy are important for estimating accurate rice crop evapotranspiration (ETc), water transfers planning, efficient irrigation management, and hydrological studies. In this study, ETc was measured and a generalized Kc curve was calculated for paddy rice in the Sacramento Valley, California. Field experiments were conducted in three rice paddy fields during the 2011–2013 growing seasons. Surface renewal analysis, after calibration using eddy covariance method, was applied to obtain sensible heat flux values from high-frequency temperature readings; latent heat flux densities were characterized by the residual of the energy balance method. The …

Estimation of Evapotranspiration by Hargreaves Formula and Remotely Sensed Data in Semi-arid Mediterranean Areas

1997

Abstract A methodology is proposed for estimating evapotranspiration by Hargreaves formula and image analysis of remotely sensed data. At first, for a large sicilian basin (Belice basin), theactualevapotranspiration values are estimated by the energy balance equation, spectral data of two Landsat TM images and ground agrometereological measurements. Then theseactualevapotranspiration estimates and thereferenceevapotranspiration values obtained by a slightly modified Hargreaves formula, which incorporates the outgoing short-wave radiation and an albedo coefficient equal to 0·23, are used for calculating suitable crop coefficients. Finally, the minimum area of each land-use map unit, obtained…

Estimate of the alpha parameter in an oat crop under rain-fed conditions

2012

In this article, we estimated the alpha parameter of the Priestley–Taylor model under rain-fed conditions. This study was conducted in an oat crop, from 7 September to 22 October 2009, in a region of subhumid plains (Tandil, Argentina). An energy balance station was installed within the experimental field to monitor its development. The alpha parameter value obtained was 1.41 ± 0.01, which led to an overestimation of the evapotranspiration of just 2% and a relative error in estimating evapotranspiration of 8%. The results suggest that the alpha parameter obtained is adequate in estimating the evapotranspiration of oat crops or similar crops in subhumid plains of Buenos Aires, Argentina. Cop…

Critical analysis of empirical ground heat flux equations on a cereal field using micrometeorological data

2009

The rate at which the net radiation is transferred to the soil as ground heat flux varies with surface characteristics. Surface energy balance algorithms use empirical relationships taking into account the effects of the canopy cover to insulate the soil through vegetation indexes, the soil capacity to absorb incoming net radiation via the albedo, and the surface temperature promoting the energy transfer. However empirical relationships are often dependent on local conditions, such as the soil humidity and vegetation type. Ground heat flux assumes a minimum value in case of full canopy cover and a maximum value for dry bare soil. Aim of the present research is the critical analysis of some …