Dissertações em Ciências Ambientais (Mestrado) - PPGCA/IG
URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/2855
O Mestrado Acadêmico em Ciências Ambientais teve início em 2005 e funciona no Programa de Pós-Graduação em Ciências Ambientais (PPGCA) do Instituto de Geociências (IG) da Universidade Federal do Pará (UFPA) em parceria com o Museu Paraense Emílio Goeldi (MPEG) e a Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA/Amazônia Oriental).
Navegar
Navegando Dissertações em Ciências Ambientais (Mestrado) - PPGCA/IG por Orientadores "COHEN, Júlia Clarinda Paiva"
Agora exibindo 1 - 4 de 4
- Resultados por página
- Opções de Ordenação
Item Acesso aberto (Open Access) Evento de friagem na Amazônia Central e sua influência nas variáveis micrometeorológicas e na química da atmosfera(Universidade Federal do Pará, 2018-09-04) CAMARINHA NETO, Guilherme Francisco; CARIOCA, Alessandro Araújo; http://lattes.cnpq.br/6188087583954899; COHEN, Júlia Clarinda Paiva; http://lattes.cnpq.br/0293299378753887The central focus of this study was to better understand the environmental interference caused by the “Friagem” phenomenon in a forest region in the center of the Amazon, considering the micrometeorological and atmospheric chemistry aspects. In order to do so, we used data from the Amazon Tall Tower Observatory (ATTO) research site, which is part of the Large scale Biosphere-Atmosphere program in the Amazon (LBA), data from the surface stations of the international airports of Porto Velho-RO and Manaus-AM, in addition to the reanalysis of ECMWF Era-Interim (European Center for Medium-Range Weather Forecasts) and high-resolution numerical simulations designed by JULES-CCATT-BRAMS, we investigated the impacts of the advance of the Friagem in the environment of the Amazon basin scale through the ERA-interim reanalysis, with this information a cold and dry air wave was observed penetrating the Amazon region in the South/North direction, between the days 6 and 11 July, 2014. The reanalyses of day 11 showed that the south-west flow related to the coldness converged with the easterly winds in the central region of the Amazon, and the images of the infrared channel of the satellite GOES-13 showed that the interaction between these two distinct air masses generated strong convective activity in this region, when a precipitation of 21mm was also recorded in the ATTO site. The air temperature and wind direction near the surface in Porto Velho and Manaus and above the canopy in the ATTO site were analyzed, and the arrival of the “Friagem” caused a sudden fall in temperature and a predominance of winds in the South quadrant in these regions. three localities, and these effects were seen in Porto Velho between 7 and 8 July and in Manaus and ATTO site between 9 and 11 July. From this, the analyzes were concentrated in the records of the Instant tower at the ATTO site, where it was observed that the reduction of the incident radiation due to convective activity on July 11, implied a reduction in O3 concentrations from 15:00 UTC of this day, indicating an indirect interference of the “Friagem” in the chemistry of the atmosphere. Finally, the numerical simulations revealed that the cold-related flow is shallow and restricted to vertical levels of less than 500 m, in addition, the simulations also showed that the breeze circulations of the Balbina lake possibly did not influence the atmospheric chemistry in the region of the ATTO site at the time of the cold, although the center of the lake presented higher concentrations of NO2, CO and O3 in comparison to the surface of the forest in its surroundings.Item Acesso aberto (Open Access) A influência do Arco do Desmatamento sobre o ciclo hidrológico da Amazônia(Universidade Federal do Pará, 2008) BELTRÃO, Josivan da Cruz; GANDU, Adilson Wagner; http://lattes.cnpq.br/8491359374260645; COHEN, Júlia Clarinda Paiva; http://lattes.cnpq.br/0293299378753887This study aimed to quantify the changes in the hydrological cycle of the Amazon due the deforestation, mainly in area called "Arc of Deforestation". Thus, experiments were performed using the BRAMS (Brazilian Regional Atmospheric Modeling System) model include the submodel of dynamic vegetation GEMTM (General Energy and Mass Transport Model). We investigated the impacts caused by the actual Arc of Deforestation compared to intact forest, as well as future changes, caused by the increase of deforestation up to 2050. As surface boundary conditions we used scenarios from empirical models of deforestation for 2002 and 2050. The increase in the Arc of Deforestation showed a complex interaction on variable analysed. For example, the precipitation showed heterogeneous distribution with positive and negative anomalies that were consistent with the anomalies of other variables, such as evapotranspiration and divergence of moisture. Also, we found the influence of the great rivers and topography on precipitation distribution. The balance of radiation and energy has been affected by deforestation, mainly over area which the forest was substituted by pastures due the surface albedo had been changed. The impact of current deforestation to intact forest showed changed only over areas most affected by deforestation, while to deforestation in the future (2050) the hydrological cycle change reaches whole the Amazon region.Item 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/0293299378753887The 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).Item Acesso aberto (Open Access) Simulações de ondas de gravidade na camada limite noturna amazônica e sua influência nas trocas de ozônio e monóxido de carbono.(Universidade Federal do Pará, 2020-06-30) MORAES, Eiky Tatsuya Ishikawa de; DIAS JÚNIOR, Cléo Quaresma; http://lattes.cnpq.br/9857237626091379; https://orcid.org/0000-0003-4783-4689; COHEN, Júlia Clarinda Paiva; http://lattes.cnpq.br/0293299378753887; https://orcid.org/0000-0003-2048-8915The main objective of this work is to investigate the influence of topography on the generation of gravity waves (OGs) and their consequent implications on gas transport between different parts of the atmosphere, at night, at the ATTO (Amazon Tall Tower Observatory) experimental site, in the municipality of São Sebastião de Uatumã-AM, in the central region of the Amazon. The experimental data was collected at the ATTO site in the Instant tower of 81 m height. To reach the results, we used Morlet's wavelet transform method, image from the GOES-13 satellite in the infrared band, reanalysis from the ECMWF Era-Interim (European Centre for Medium-Range Weather Forecasts) and numerical simulations of the mesoscale model BRAMS (Brazilian Regional Atmospheric Modeling System) version 5.3. Firstly, an occurrence of OG on the night of the 12th to the 13th of November 2015, through the analysis via wavelet transform. Satellite images showed that rain events did not occur on the night in question, which allowed the annulment of the possibility that the OG had a convective origin. The ECMWF Era-Interim reanalysis were then used, and wave signals were also identified in the air temperature, vertical component of the wind and gases such as CO and O3. Two experiments were then simulated in the JULES-CCATT-BRAMS model, one with the real topography of the region (SC) and the other with the removal of the topography (ST). The simulations results showed up that the presence of the topography intensifies the OG action in air temperature oscillations, in the movement of vertical wind components and in air floatage. Furthermore, the wave transported O3 and CO from burn regions to the ATTO site, a fact that is not significantly observed in ST simulation. Lastly, the simulations proved that the topography had a relevant role in the generation and intensification of OG and its actions in scalars transport near the surface.