101 research outputs found

    The role of coastal urbanisation in enhancing turbulence and land-sea breeze

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    Recent increasing urbanisation phenomena it is expected will alter the morphology and texture of wide territories leading to a strong changes in the materials, from natural to man-made, at the surface. This land-use change can strongly affects the energy partition of the solar radiation substantially increasing the intensity of the sensible heat flux (along with the anthropogenic heat contribution). The sites which present local anemological circulation, such as the breeze regimes, can result more sensible to enhanced turbulence, and environmental impacts must be taking into account when considering managing plans for residential or touristic populations

    Determination Of The Adaptability And Stability Of Soybean Cultivars In Different Locations And At Different Sowing Times In Paraná State Using The Ammi And Eberhart And Russel Methods

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    This study aimed to evaluate the adaptability and phenotypic stability of 10 soybean genotypes in 12 environments in Paraná state by using the additive main effects and multiplicative interaction analysis (AMMI) and Eberhart and Russell models. The assays were conducted in a randomized complete block design with three replicates, in the 2010/2011 season in four locations in Paraná state (Assaí, São Pedro do Ivaí, Cornélio Procópio, and Marilândia do Sul), and with three sowing dates (15/-20/10/10; 29/10-03/11/10; 15/-20/11/10). The cultivars tested with Roundup Ready® technology included SYN 1049, SYN 1152, SYN 1059, SYN 3358, SYN 1163, SYN 1157, V-MAX, FT Campo Mourão, BMX Potência, and SYN 9070. The yield character was analyzed. Data were submitted to analysis of variance and the adaptability and stability were then analyzed. The results of the AMMI and Eberhart and Russell models were somewhat consistent for the stability parameter only. The AMMI analysis was able to capture 66% of the variance associated with residue no additives, of which 43.18% was retained in the first principal component of interaction and 23.58%, in the second component. This is sufficient to explain the genotype × environment interaction. The SYN 1059, SYN 1163, and VMAX genotypes are distinguished by their considerably higher yield and productive adaptation. In the AMMI analysis, the cultivar SYN 1163 showed commercial promise among the other cultivars for high grain yield performance, adaptation, and response predictability.3763973398

    Boundary layer convective-like activity at Dome Concordia, Antarctica

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    The paper presents the micro-meteorological field experiment carried out at the plateau station of Dome Concordia (3300 m a.s.l.) during the Antarctic summer of 1997. The experiment dealt with the study of the trends of boundary layer features and the characteristics of the surface energy and momentum exchanges. A monostatic Doppler sodar, fast-response sensors and radiometers were used for this study. The experiment was part of a program that aims to assess the role of the continental polar regions in shaping the surface circulation over Antarctica. In spite of the markedly stable conditions found throughout the investigated period, some convective-like activity was detected during the warmer hours of the day

    MICROMETEOROLOGICAL AND SAP FLOW MEASUREMENT OF WATER VAPOUR EXCHANGES IN OLIVE: SCALING UP FROM CANOPY TO ORCHARD

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    A comparison of water consumption evaluated at tree and orchard level was carried out in a commercial olive orchard located in Sicily using up-scaled sap-flow evapotranspiration estimations and eddy covariance measurements. Sap flow probes were installed on olive trees placed in one of the four plots characterizing a heterogeneous orchard. Trees were chosen, from a preliminary footprint analysis, in correspondence to the peak of the “relative normalized contribution” to flux for the prevailing wind conditions measured by an eddy covariance station localized in the central part of the orchard. Tree-age and planting density as well as main tree and orchard characteristics (Leaf Area per tree, within plot distribution of Trunk Cross Sectional Area TCSA, height and canopy diameter), were used to characterize the plot-to-plot differences. Both TCSA and LAI adopted as scaling parameters showed a high performance. A good agreement between ETec (daily integral of EC-estimated evapotranspiration) and ETsf (up-scale sap flow ET estimate) was found in correspondence of limited canopy or soil evaporation conditions (absence of rain, dew, irrigation supply). Eddy covariance can be considered a reliable reference for up-scaled sap flow estimations of ET, and sap flow can be used as a replacement (proxy) of eddy covariance when atmospheric conditions invalidate the application of this technique to assess ET

    Characteristics of the boundary layerat Ny-Ålesund in the Arctic during the ARTIST field experiment

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    A preliminary analysis of boundary layer data acquired during the Arctic Radiation and Turbulence Interaction Study Experiment (ARTIST) at Ny-Ålesund (Spitzbergen) in 1998 is presented. As expected, the wind fi eld and the thermal structure of the boundary layer are strongly infl uenced by the katabatic fl ow blowing along the Kongsfjorden. In particular, if the large scale circulation has a component along the same direction, the resulting low level wind reaches velocities comparable with geostrophic wind. Stable to neutral conditions occurred most of the time, sustaining inversion or spiky layers respectively, depending on the wind intensity. The behaviour of some micrometeorological parameters was examined in relation to the general fl ow pattern and the characteristics of this area. The highest values of surface sensible heat fl ux (with negative sign) were observed during daytime, in presence of forced convection, due to the transfer of warmer upper layer air into the surface layer

    Recent results from the Arctic Radiation and Turbulence Interaction STudy (ARTIST) project

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    Ground-based measurements were conducted at Ny-˚Alesund in the Svalbard Islands in the framework of the research project ARTIST (Arctic Radiation and Turbulence Interaction STudy) funded by the European Communities. Key objectivesof the campaign were: 1) provide all participantswith ground reference data as input to models describing the development of the atmospheric boundary level, 2) compute the surface roughness length in order to characterise the surface of the site, 3) parameterise the surface energy exchanges, calculating the surface radiation flux, the sensible and latent heat fluxes, and 4) obtain the surface energy balance during both clear and cloudy sky conditions. The cloud radiative forcing has been also estimated. Final results of the analysis of the data set are presented

    The blackberry breeding program of "Embrapa Clima Temperado": an update.

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    In terms of breeding perennial plants, the Embrapa's blackberry breeding program is relatively recent. It started between the end of the 1970s and beginning of the 1980s with a very limited number of cultivars plus a fairly good number of seeds from hybridizations made at the University of Arkansas, USA. Objective: this paper aim to present, in a summarized way, the current stage and recent achievements regarding the top priorities of the breeding program Methodology: Controlled hybridizations is the main method used and adaptation to mild winters conditions besides a higher ratio (sugar/acid contents) are among the main objectives. Results: Other objectives include high productivity, large size and firm fruits, good post-harvest conservation, erect, thornless canes and harvest period at different time of ?Tupy,? the most important one, in Brazil. Implications: It is believed that in the coming years, the Brazilian market will learn to like fresh blackberry, mainly considering the release of ?BRS Cainguá? and others that hopefully will follow. Conclusion: The present status of the program and achievements related to the main goals are discussed. Advanced selections with potential to become a future cultivar are briefly described, emphasizing next probable releases.Título em espanhol: El programa de mejora de blackberry de "Embrapa Clima Temperado": una actualización

    Surprisingly small HONO emissions from snow surfaces at Browning Pass, Antarctica

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    Measured Fluxes of nitrous acid at Browning Pass, Antarctica were very low, despite conditions that are generally understood as favorable for HONO emissions, including: acidic snow surfaces, an abundance of NO<sub>3</sub><sup>-</sup> anions in the snow surface, and abundant UV light for NO<sub>3</sub><sup>-</sup> photolysis. Photochemical modeling suggests noon time HONO fluxes of 5&ndash;10 nmol m<sup>-2</sup> h<sup>-1</sup>; the measured fluxes, however, were close to zero throughout the campaign. The location and state of NO<sub>3</sub><sup>-</sup> in snow is crucial to its reactivity. The analysis of soluble mineral ions in snow reveals that the NO<sub>3</sub><sup>-</sup> ion is probably present in aged snows as NaNO<sub>3</sub>. This is peculiar to our study site, and we suggest that this may affect the photochemical reactivity of NO<sub>3</sub><sup>-</sup>, by preventing the release of products, or providing a reactive medium for newly formed HONO. In fresh snow, the NO<sub>3</sub><sup>-</sup> ion is probably present as dissolved or adsorbed HNO<sub>3</sub> and yet, no HONO emissions were observed. We speculate that HONO formation from NO<sub>3</sub><sup>-</sup> photolysis may involve electron transfer reactions of NO<sub>2</sub> from photosensitized organics and that fresh snows at our site had insufficient concentrations of adequate organic compounds to favor this reaction

    Genetic progress in 53 years of the Peach Breeding Program of Embrapa: Fresh market cultivars.

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    Em 1963, começou na Estação Experimental de Pelotas, hoje Embrapa Clima Temperado, um programa de melhoramento de pessegueiro cujo objetivo fundamental era desenvolver cultivares adaptadas a condições de inverno ameno. Inicialmente, a prioridade era a obtenção de cultivares produtoras de frutos para enlatamento, mas, ao longo dos anos, cultivares para o mercado fresco adquiriram a mesma importância. Este artigo analisa dados de 84 cultivares, tipo mesa, desenvolvidos em Pelotas, de 1964 a 2017, focando nos seguintes parâmetros: época de maturação, período de desenvolvimento do fruto, massa média dos frutos, número de frutos por planta, produção por planta e conteúdo de sólidos solúveis das frutas. Inicialmente, os dados foram tabulados, divididos em dois períodos (1964-1984 e 1985-2017), sendo então realizada a análise estatística descritiva, seguida por uma análise de modelos mistos e estimativa do progresso genético via meta-análise. Os resultados mostraram uma redução no período de desenvolvimento dos frutos das cultivares tipo mesa, pertencentes a esse programa. Houve ainda uma ampliação do período de colheita (do fim de setembro ou início de outubro até janeiro), com uma leve tendência à maior precocidade. Verificou-se um ganho genético para produção por planta, correspondendo a 1.17 e 2.25% ao ano, para os períodos de 1964-1984 e 1985-2017, respectivamente.DOI: https://dx.doi.org/10.1590/0100-29452023146
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