392 research outputs found

    An initial intercomparison of atmospheric and oceanic climatology for the ICE-5G and ICE-4G models of LGM paleotopography

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    This paper investigates the impact of the new ICE-5G paleotopography dataset for Last Glacial Maximum (LGM) conditions on a coupled model simulation of the thermal and dynamical state of the glacial atmosphere and on both land surface and sea surface conditions. The study is based upon coupled climate simulations performed with the ocean–atmosphere–sea ice model of intermediate-complexity Climate de Bilt-coupled large-scale ice–ocean (ECBilt-Clio) model. Four simulations focusing on the Last Glacial Maximum [21 000 calendar years before present (BP)] have been analyzed: a first simulation (LGM-4G) that employed the original ICE-4G ice sheet topography and albedo, and a second simulation (LGM-5G) that employed the newly constructed ice sheet topography, denoted ICE-5G, and its respective albedo. Intercomparison of the results obtained in these experiments demonstrates that the LGM-5G simulation delivers significantly enhanced cooling over Canada compared to the LGM-4G simulation whereas positive temperature anomalies are simulated over southern North America and the northern Atlantic. Moreover, introduction of the ICE-5G topography is shown to lead to a deceleration of the subtropical westerlies and to the development of an intensified ridge over North America, which has a profound effect upon the hydrological cycle. Additionally, two flat ice sheet experiments were carried out to investigate the impact of the ice sheet albedo on global climate. By comparing these experiments with the full LGM simulations, it becomes evident that the climate anomalies between LGM-5G and LGM-4G are mainly driven by changes of the earth’s topography

    Sensitivity of the sorghum yield to individual changes in climate parameters: modelling based approach.

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    Based on sensitivity analyses the effect of changing in climate on sorghum has been investigated. This has been achieved by conducting crop modeling experiments carried out with weather observations and output of global climate models. As can be anticipated results demonstrated that the sorghum yield is more sensitive to rainfall, solar radiation and CO2 concentration. However, the increase in CO2 concentration has a positive effect on yield in years that the crop is submitted to water stress. This effect is extremely reduced under well watered conditions and therefore is subject to the climate inter-annual variability. Accumulated solar radiation along the sorghum cycle below 1900 MJ m?2 has also been shown to reduce the yield. Compared to other weather variables the sorghum yield is less sensitive to changes in relative humidity. In this sense, changes in stomatal closure and therefore photosyntesis is not highly dependent on water vapor pressure. These finds can be applied for both climate observations and global models output

    Characterization of a settled dust event in an urban area affected by industrial activities

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    Trabalho apresentado em 7th Iberian Meeting Aerosol Science and Technology – RICTA19, 2019, Lisbon, PortugalN/

    Nitrogen Used Strategies Of Nodulated Amazonian Legume: Inga Edulis

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    Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Symbiotic nitrogen fixation in legumes is strongly diminished by mineral nitrogen. Nevertheless, recent work with some tropical legumes revealed low sensitivity to mineral nitrogen or even enhancement of nodulation by ammonium. Thus, in this study, we investigated plant growth and nodulation of Inga edulis over a period of 128 days using different sources of nitrogen, i.e. ammonium (15 mM), nitrate (15 mM) and symbiotic nitrogen fixation. Plant growth was evaluated through dry mass, height, stem diameter and root/shoot ratio as well as nodulation by nodule number and dry mass. Nitrate, ureides and total amino acids were determined in roots, shoots and xylem sap. All three nitrogen sources were found to stimulate growth relative to the noninoculated N-free control, however ammonium was the most effective. Nodulation, both nodule number and mass, was strongly reduced by nitrate but not ammonium. The transport of total amino acids in the xylem sap was stimulated by ammonium without change in the composition with asparagine predominating in all treatments. Inga edulis can benefit from fertilisation with ammonium since even at high concentrations growth was improved without impairing nodulation, a condition appropriate for restoration of soil conditions.29119National Institute of Amazonian Research (MCTI-INPA)National Council for Scientific and Technological Development (CNPq, Brazil)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Contribution of micro‐PIXE to the characterization of settled dust events in an urban area affected by industrial activities

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    This study aimed to identify possible sources of settled dust events that occurred in an urban area nearby an industrial park, which alarmed the local population. Settled dust was collected in January 2019 and its chemical characterization was assessed by micro-PIXE, focusing on a total of 29 elements. Comparison with chemical profiles of particulate matter from different types of environment was conducted, along with the assessment of crustal enrichment factors and Spearman correlations, allowing to understand which sources were contributing to this settled dust event. A nearby industrial area’s influence was identified due to the contents of Fe, Cr and Mn, which are typical tracers of iron and steel industries.info:eu-repo/semantics/publishedVersio

    Citizens involvement in the assessment of atmospheric contamination in an industrial area

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    Trabalho apresentado em 25th International Clean Air and Environment Conference CASANZ 2021, 17-21 de maio 2021, onlineN/

    Liquid chromatography–diode array detection–electrospray ionisation mass spectrometry/nuclear magnetic resonance analyses of the anti-hyperglycemic flavonoid extract of Genista tenera Structure elucidation of a flavonoid-C-glycoside

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    The anti-hyperglycemic flavonoid extract obtained from Genista tenera was first studied by liquid chromatography (LC)–diode array detection (DAD) which showed the presence of two major compounds. One of them was identified as genistein-7-O-glucoside. Luteolin-7-O-glucoside was detected as a minor constituent, while luteolin-7,3′-di-O-glucoside and rutin were found in trace amounts. LC–DAD–ESI–MS and NMR were used to confirm the structure of these compounds and allowed the elucidation of the structure of the unknown major compound, which is the flavonoid 5,7,4′-trihydroxyisoflavone-8-C-glucoside.info:eu-repo/semantics/publishedVersio

    Citizens’ involvement in air biomonitoring with strawberry plants

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    Trabalho apresentado em EUDRES Citizen Science Conference, 28-29 de junho 2023, Barreiro, PortugalN/

    Modeling of Soybean under Present and Future Climates in Mozambique

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    Citation: Talacuece, M. A. D., Justino, F. B., Rodrigues, R. D., Flores, M. E. P., Nascimento, J. G., & Santos, E. A. (2016). Modeling of Soybean under Present and Future Climates in Mozambique. Climate, 4(2), 14. doi:10.3390/cli4020031This study aims to calibrate and validate the generic crop model (CROPGRO-Soybean) and estimate the soybean yield, considering simulations with different sowing times for the current period (1990-2013) and future climate scenario (2014-2030). The database used came from observed data, nine climate models of CORDEX (Coordinated Regional climate Downscaling Experiment)-Africa framework and MERRA (Modern Era Retrospective-Analysis for Research and Applications) reanalysis. The calibration and validation data for the model were acquired in field experiments, carried out in the 2009/2010 and 2010/2011 growing seasons in the experimental area of the International Institute of Tropical Agriculture (IITA) in Angonia, Mozambique. The yield of two soybean cultivars: Tgx 1740-2F and Tgx 1908-8F was evaluated in the experiments and modeled for two distinct CO2 concentrations. Our model simulation results indicate that the fertilization effect leads to yield gains for both cultivars, ranging from 11.4% (Tgx 1908-8F) to 15% (Tgx 1740-2Fm) when compared to the performance of those cultivars under current CO2 atmospheric concentration. Moreover, our results show that MERRA, the RegCM4 (Regional Climatic Model version 4) and CNRM-CM5 (Centre National de Recherches Meteorologiques - Climatic Model version 5) models provided more accurate estimates of yield, while others models underestimate yield as compared to observations, a fact that was demonstrated to be related to the model's capability of reproducing the precipitation and the surface radiation amount

    Avaliação de doses e datas de aplicação de nitrogênio no feijão-comum por meio de modelo de simulação.

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    A adubação nitrogenada é um dos fatores responsáveis pelo alcance de altas produtividades na cultura do feijoeiro, portanto, o manejo adequado do nitrogênio é fundamental para que as necessidades da cultura sejam atendidas, garantindo boas produtividades e diminuindo o custo de produção e os riscos de poluição ambiental. O objetivo deste trabalho foi avaliar in silico o efeito de diferentes doses e épocas de aplicação de nitrogênio na produtividade do feijão-comum, em três safras de cultivo, em diferentes datas de semeadura, para as condições edafoclimáticas de Goiás.Evento online
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