Teste de Diferentes Parametrizações da Turbulencia Utilizando um Modelo de Disperssão

Neste trabalho, estima-se a concentração de contaminantes emcondições de atmosfera neutra e convectiva utilizando parametrizaçõesda turbulência propostas por Hanna (1982) e por Degrazia et al. (2000).Um modelo de partículas estocástico lagrangeana foi utilizado, comforçantes medidos em dois experimentos clássicos da literatura: experimentosde Copenhagen e Prairie

Comparação de Diferentes Parametrizações da Turbulência numa Atmosfera Neutra

Comparação de diferentes parametrizações da turbulêncianuma atmosfera neutr

Estudo da Difusão Empregando´Parâmetros Turbulentos que Descrevem a Capacidade de Mistura da Camada Limite Planetária

Estudo da difusão empregando parâmetros turbulentos quedescrevem a capacidade de mistura daCamada Limite Planetári

Estimativa das Trocas Líquidas de co2 para Diferentes Coberturas de Solo em um Agroecossitema na Região Oeste do Pará, km77, em Santarém, PA

Estimativa das trocas líquidas de CO2 para diferentescoberturas de solo em um agroecossitema na região oestedo Pará, km77, em Santarém, P

Proposal of a new autocorrelation function in low wind speed conditions

Abstract In this study a new mathematical expression to describe the observed meandering autocorrelation functions in low-wind speed is proposed. The analysis utilizes a large number of best fit curves to show that the proposed theoretical function well reproduces the general form and the negative lobes characterizing the experimental meandering autocorrelation function. Further, the good agreement of the measured autocorrelation curves with the proposed algebraic autocorrelation function allows to calculate the magnitudes of the meandering period and of the loop parameter. The results agree with the values presented and discussed in the literature. Therefore, the new formulation describing experimental meandering autocorrelation functions can be used to simulate the dispersion of contaminant during low wind episodes and to determine relevant meandering parameters

Seasonality of soil water exchange in the soybean growing season in southern Brazil

The processes of water transfer in the soil-plant-atmosphere system are strongly affected by soil use and management. Differences in the dynamics of soil water transfer between no-tillage (NT) and conventional tillage (CT) practices during a soybean (Glycine max) growing season in southern Brazil were assessed in this study. All the water balance components were analyzed during the soybean growing season (2009/2010). Rainfall, runoff, soil water storage and hydro-physical soil properties were analyzed under two tillage systems. The land-atmosphere water vapor exchanges, obtained from eddy covariance stations, were analyzed with regard to the soybean agroecosystem. Characterizations of soil water storage were also formulated in the 2006/2007 and 2008/2009 soybean growing seasons under the NT system. During the periods without rain, the soil water content under NT was greater than under CT. The soil superficial layer, more porous under NT, contributed to less runoff during rainy events. Moreover, under NT conditions the water supply was always high, between 0.2 - 0.5 m. The total evapotranspiration in the soybean agroecosystem growing season was 410.8 mm