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Registros recuperados: 17 | |
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ACOSTA, J. F.; CARDOZO, N. P.; MARIN, F. R.. |
Avaliou-se o desempenho do método de estimativa do saldo de radiação proposto por ALLEN, 1998, em experimentos de culturas de girassol, amendoim, café, limão e grama, através de regressões lineares com base nos indicadores estatísticos coeficiente de correlação r?, índice de Willmott ?d? e índice de desempenho ?c?. Segundo os critérios de avaliação do índice ?c?, o método proposto por ALLEN, 1998 representa de forma satisfatória os dados de saldo de radiação, sendo obtidos os desempenhos equivalentes a 0,79 (muito bom) para as culturas de girassol e grama e de 0,96; 0,86 e 0,88 (ótimo) para as culturas de amendoim, café e limão, respectivamente. |
Tipo: Anais e Proceedings de eventos |
Palavras-chave: Saldo de radiação; Índice de Willmott “d”; Índice de desempenho “c”; Coeficiente de correlação “r”; Modelagem; Indicadores estatísticos; Modelling; Willmott index.; Net radiation. |
Ano: 2009 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/513474 |
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Vanomark,Giuliana Mairana Morais de Sousa; Espínola Sobrinho,José; Bezerra,José Renato Cortez; Santos,Carlos Antonio Costa dos; Azevedo,Pedro Vieira de; Silva,Saulo Tasso Araújo da; Bezerra,Bergson Guedes. |
ABSTRACT The Mossoró-Assu-Baraúna district, Rio Grande do Norte State (RN), is recognized by the intense production of horticulture, mainly muskmelon for export. However, this region is often devastated by intense droughts. Thus, the muskmelon production is predominantly under irrigated condition and, due to constant threat of water resources collapse on the region, a rigorous irrigation water management in the region is needed. The main objective of this article was to analyze the seasonal pattern of energy balance partitioning and evapotranspiration on irrigated muskmelon crop on the region around Mossoró-RN. The study was carried out in two areas of commercial production of muskmelons in the Mossoró-Assu-Barúna district, during two growth seasons from... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Mossoró-Assu-Baraúna district; Net radiation; Latent and sensible heat fluxes; Soil heat flux. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052018000100168 |
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TEIXEIRA, A. H. de C.; HERNANDEZ, F. B. T.; ANDRADE, R. G.; LEIVAS, J. F.; BOLFE, E. L.. |
The energy balance (EB) components were quantified in a commercial farm with corn crop, irrigated by central pivots, in the Northwestern side of São Paulo state, Southeast Brazil. The SAFER (Simple Algorithm For Evapotranspiration Retrieving) was applied to retrieve the latent heat flux (λE), considering six pivots, covering irrigated areas from 74 to 108 ha. With λE quantified and considering soil heat flux (G) as a fraction of net radiation (Rn), the sensible heat flux (H) was acquired as a residual in the energy balance equation. Seven Landsat satellite images, covering all corn crop stages from 23 April 2010 to 29 August 2010, allowed relating the energy balance components according to the accumulated degree-days (DDac) from the... |
Tipo: Artigo de periódico |
Palavras-chave: Latent heat flux; Soil heat flux.; Sensible heat flux; Net radiation. |
Ano: 2014 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1001276 |
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TEIXEIRA, A. H. de C.; LEIVAS, J. F.; RONQUIM, C. C.; SILVA, G. B. S. da; VICTORIA, D. de C.. |
Under land and climate change scenarios, agriculture has experienced water competitions among other sectors in the São Paulo state, Brazil. On the one hand, in several occasions, in the northeastern side of this state, nowadays sugar-cane is expanding, while coffee plantations are losing space. On the other hand, both crops have replaced the natural vegetation composed by Savannah and Atlantic Coastal Forest species. Under this dynamic situation, geosciences are valuable tools for evaluating the large-scale energy and mass exchanges between these diffe rent agro-ecosystems and the lower atmosphere. For quantification of the energy balance components in these mixed agro-ecosystems, the bands 1 and 2 from the MODIS product MOD13Q1 we re used throughout SA... |
Tipo: Artigo de periódico |
Palavras-chave: Net radiation; Latent heat flux; Sensible heat flux; Agro-ecosystems; Saldo de radiação; Fluxo de calor latente; Fluxo de calor sensível; Agro-ecossistemas.; Sensoriamento Remoto.; Remote sensing.. |
Ano: 2016 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1055656 |
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TEIXEIRA, A. H. de C.; SCHERER-WARREN, M.; HERNANDEZ, F. B. T.; ANDRADE, R. G.; LEIVAS, J. F.. |
In the Brazilian semi-arid region, the intensification of agriculture results in a change of natural vegetation by irrigated crops. To quantify the contrast between these two ecosystems, the large-scale values of water productivity components were modelled in Petrolina (PE) and Juazeiro (BA) municipalities. The SAFER (Simple Algorithm For Evapotranspiration Retrieving) algorithm was used to acquire evapotranspiration (ET), while the Monteith's radiation model was applied for estimating the biomass production (BIO). Moderate Resolution Imaging Spectroradiometer (MODIS) satellite images were used together with agro-meteorological data. In Petrolina and Juazeiro, the mean monthly ET values for irrigated crops were 938 and 739 mm·month−1, with the... |
Tipo: Artigo de periódico |
Palavras-chave: Net radiation; Surface resistance.; Evapotranspiration; Biomass production.. |
Ano: 2013 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/971815 |
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Silva,Bernardo B. da; Braga,Alexandra C.; Braga,Célia C.; Oliveira,Leidjane M. M. de; Montenegro,Suzana M. G. L.; Barbosa Junior,Bernardo. |
ABSTRACT The surface albedo plays an important role in the exchanges of energy and mass in the planetary boundary layer. Therefore, changes in albedo affect the balance of radiation and energy at the surface, which can be detected with its monitoring. Albedo determination has been performed through various sensors, but there is not yet any publication dealing with albedo calculation procedures using OLI (Operational Land Imager) - Landsat 8 images. The objective of the study is to present the procedures for computing the albedo with OLI images and map it in irrigated areas of the São Gonçalo Irrigated District, PB, Brazil. Images of the year 2013, path 215 and row 65, were selected. The data necessary for calculating the albedo were extracted from each... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Radiance; Spectral reflectance; Atmospheric transmittance; Net radiation. |
Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662016000100003 |
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BOSI, C.; PEZZOPANE, J. R. M.; SENTELHAS, P. C.. |
The aim of the present study was to assess the effect of Eucalyptus trees in a silvopastoral system on the microclimate and the capacity of that to mitigate the effects of climate change on pasturelands. This study included an open pasture of Piatã palisadegrass and an adjacent pasture that contained both palisadegrass and Eastto-West rows of Eucalyptus trees, with 15 m between rows, 2 m between trees within rows. The micrometeorological measurements were collected at several distances from the tree rows and in the open pasture. The silvopastoral system was associated with greater between-row shading when solar declination was high and greater near-tree shading when solar declination was around -22°. Both soil heat fl ux and temperature were infl uenced by... |
Tipo: Artigo de periódico |
Palavras-chave: Net radiation; Shading; Soil heat flux; Agroforestry; Microclimate; Windbreaks. |
Ano: 2020 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1126754 |
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TEIXEIRA, A. H. de C.; ANDRADE, R. G.; LEIVAS, J. F.; RONQUIM, C. C.; VICTORIA, D. de C.; HERNANDEZ, F. B. T.. |
A porção nordeste do Estado de São Paulo destaca-se pelas grandes áreas cultivadas com cana-de-açúcar. Considerando estas mudanças de uso da terra, um produto MODIS foi usado em conjunto com dados agrometeorológicas para a quantificação dos componentes dos balanços de energia e de água, ao longo do ano de 2012. Dois tipos de manejo foram considerados, colheita da cana com e sem queima. Para ambos os tipos de manejo, a parcela do saldo de radiação (Rn) usada como fluxos de calor latente (λE), variou de 0,27 a 0,87, enquanto que aquela para o fluxo de calor sensível (H) esteve entre 0,13 e 0,74. Com queima na colheita a cultura usou até 5% menos e 6% mais da energia disponível para, respectivamente, os processos de evapotranspiração (ET) e para... |
Tipo: Anais e Proceedings de eventos |
Palavras-chave: Saldo de radiação; Fluxo de calor latente; Fluxo de calor sensível; Latent heat flux; Sensible heat flux.; Net radiation. |
Ano: 2014 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/986242 |
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TEIXEIRA, A. H. de C.; PADOVANI, C. R.; ANDRADE, R. G.; LEIVAS, J. F.; VICTORIA, D. de C.; GALDINO, S.. |
MODIS images during the year 2012 were used for modelling of the radiation and energy balance components with the application of the SAFER algorithm (Simple Algorithm for Evapotranspiration Retrieving) in the Brazilian Pantanal area. Pixels from the main sub-regions of Barão de Melgaço (BR), Paiaguás (PA) and Nhecolândia (NH) were extracted in order to process microclimatic comparisons. In general, the net radiation (Rn) relied much more on the global solar radiation (RG) levels than on water conditions and ecosystem types, in accordance with the low Rn standard deviation values. The fraction of the available energy used as latent heat flux (λE) were, on average, 65, 50 and 49% for the BR, PA and NH sub-regions, respectively. Horizontal heat... |
Tipo: Artigo de periódico |
Palavras-chave: Evaporative fraction; Latent heat flux; Net radiation; Sensible heat flux.; Remote sensing; Wetlands.. |
Ano: 2015 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1029921 |
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Rolim,Glauco de Souza; Escobedo,João Francisco; Oliveira,Amauri Pereira. |
The quantification of the available energy in the environment is important because it determines photosynthesis, evapotranspiration and, therefore, the final yield of crops. Instruments for measuring the energy balance are costly and indirect estimation alternatives are desirable. This study assessed the Deardorff's model performance during a cycle of a sugarcane crop in Piracicaba, State of São Paulo, Brazil, in comparison to the aerodynamic method. This mechanistic model simulates the energy fluxes (sensible, latent heat and net radiation) at three levels (atmosphere, canopy and soil) using only air temperature, relative humidity and wind speed measured at a reference level above the canopy, crop leaf area index, and some pre-calibrated parameters... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Energy budget; Net radiation; Latent heat flux; Sensible heat flux; Microclimate. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162008000400001 |
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Registros recuperados: 17 | |
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