Navegando por CNPq "CNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::METEOROLOGIA::QUIMICA DA ATMOSFERA"

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Acesso aberto (Open Access)
Emissões de gases de efeito estufa de um aterro na Amazônia: simulação das emissões de metano no aterro do Aurá - Região Metropolitana de Belém, PA
(Universidade Federal do Pará, 2017-08-31) SILVA, Renato de Sousa; IMBIRIBA, Breno Cesar de Oliveira; http://lattes.cnpq.br/7979656297541988
Acesso aberto (Open Access)
Potencial do sequestro de carbono em plantios de dendezeiros para compensar as emissões de gases de efeito estufa no processo produtivo de óleo de palma
(Universidade Federal do Pará, 2017-03-24) LABAN, Duber Orlando Chinguel; VASCONCELOS, Steel Silva; ARAÚJO, Alessandro Carioca de
Currently, the oil palm plantations are expanding in the Brazilian Amazon, where there are the optimal conditions for their development. The limitation of culture is an important factor for the maintenance of primary areas in the Amazon. Therefore, to know the characteristics of the culture within a productive context it is necessary to apply methodologies that help the executors of the companies to take into account the carbon emissions of the product. Some studies have been adopting methodologies to determine the greenhouse gas emissions emitted in the palm oil production process, through life cycle assessment applications. In this scenario, this work estimated the carbon stocks in the hybrid palm Interspecific (HIE) (Elaeis oleifera cortés x Elaeis guineensis jacq) over 25 years (productive time of the palm) and later to inventory greenhouse gas emissions from the palm oil production process at Marborges SA. The values show to hybrid palm oil, a carbon sequestration of 0.49 Mt CO2 in 25 years and emissions from the productive process are recorded at 0.39 Mt CO2eq. In addition, it was estimated that in the native vegetation areas of the company, the sequestration registered 4.5 Mt CO2, more than the palm plantations. Finally, it can be concluded that within the environmental context the compensation of the gases emitted in the production process of palm oil should happen in pasture areas only or areas without vegetation allied to the maintenance of the native vegetation.
Acesso aberto (Open Access)
Simulações de linhas de instabilidade continentais e a formação de correntes de densidade superficiais ricas em ozônio
(Universidade Federal do Pará, 2018-02-26) MELO, Adayana Maria Queiroz de; DIAS JÚNIOR, Cléo Quaresma; http://lattes.cnpq.br/9857237626091379; COHEN, Júlia Clarinda Paiva; http://lattes.cnpq.br/0293299378753887
The main objective of this work is to better understand the increase of ozone (O3) in the surface by influence of density currents formed by the cold air of the downdrafts coming from mesoscale convective systems, using data measured in Central Amazonia, at the Manacapuru experimental site of the GoAmazon project (Observations and Modeling of the Green Ocean Amazon), reanalysis of the ECMWF Era-Interim (European Center for Medium-Range Weather Forecasts) and numerical simulations of the atmosphere with the Brazilian Regional Atmospheric Modeling System (BRAMS) model, version 5.3. To investigate surface O3 increases, the data measured in Manacapuru and ECMWF Era-Interim reanalysis were used first. Through these data, between April 10 and 14, 2014, an O3 "plume" located in the middle troposphere was observed, together with the increase in the concentrations of this gas at the surface. The images of the satellite in the infrared channel referring to this period were analyzed, and the images of the day 04/14 showed the passage of two lines of instability (LIs) by Manacapuru, the first passed at dawn and the second in the afternoon. It was observed that these LIs did not form on the North / Northeast coast of South America by the action of the sea breeze, as it commonly occurs. We then used the analysis of surface synoptic charts to understand the formation of these convective systems, and these have suggested that LIs developed within the continent, influenced by a Frontal System that reached south-eastern South America during this period. Thus, these LIs were called the Continental Instability Lines (LICONs). The experimental data measured near the surface were then examined on 04/14, and it was found that during the passage of the LICONs there were strong downdrafts in Manacapuru, since high precipitation rates and increases in the horizontal wind velocity were observed, as well as increases in atmospheric pressure, air density and surface O3 levels. Additionally, there were also sharp declines in the potential equivalent temperature values and the mixing ratio. Numerical simulations using the JULES-CCATT-BRAMS model were used to understand the three-dimensional structure of the chemistry and thermodynamics of the atmosphere during the passage of these LICONs. The simulations were able to capture the main chemical and thermodynamic characteristics of the atmosphere during the presence of the first LICON observed at dawn on 04/14. The simulation results showed that downdrafts from LICON bring cooler, drier, dense air to the surface. This downdrafts air column passed by the O3 “plume" in the middle troposphere, formed rich gas density currents and low level jets were induced near the surface and spread the O3. Finally, this cleaner air column reduced surface carbon monoxide (CO) levels, and higher O3 levels were responsible for the increase in surface nitrogen dioxide (NO2).