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).
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Item Acesso aberto (Open Access) Análise meteorológica no estabelecimento de plântulas do açaizeiro (Euterpe oleracea Mart.), na APA ilha do Combu, Belém, Pará, Brasil(Universidade Federal do Pará, 2011-03-29) FREIRE, Antonio Sérgio Cunha; JARDIM, Mario Augusto Gonçalves; http://lattes.cnpq.br/9596100367613471; VITORINO, Maria Isabel; http://lattes.cnpq.br/4570131095902916The objective of this work was to better comprehend the correlation between the meteorologic variables, solar radiation soil diffuse incident, the air temperature, relative humidity, and the precipitation in the subcanopy of the lowland forest in enviromental protection – Combu Island, in function of the natural regeneration of the forest, through the analysis of survival, mortality and birth in acai berry seedlings, species (Euterpe oleracea Mart.), between April 2010 and January 2011. An automatic meteorologic station was installed on the Combu Island that continually collected and registered the meteorologic data, producing hourly averages for each variable. Six plots were demarcated on the perimeter of the station, where one thousand sevent two acai berry seedlings were indentified and monitored. The number of living, dead, and new seedlings was monitored every two weeks. After integrating the biological data, they were correlated with the meteorological variables, and it was found that the precipitation and relative air humidity were the factors that best correlated with the survival of the seedlings with a value of .74 and .68, respectively. followed by the solar radiation soil diffuse incident in the subcanopy of the lowland, whose correlation was .42. The entry of solar radiation upwards of an average 391 W/m² (average for the observation period) suggests the determination of the higher death idexes of acai berry seedlings in the months of may and july, due to the absence of cloud cover and the lack of precipitation. Analyzing the entry of new seedlings was intially inhibited due to the rain and elevated relative air humidity in the months of April and May. After this period, there was a decrease in average rainfall and in humidity, thus providing ideal conditions for germination, probably potentiated by the elevation of solar radiation. Throughout the study period it was noted that same influence in the El Niño the natural regeneration of acai in the lowlands of Combu had the highest conservation of the population ocurred after the first part of June, with 71% survival, 29% death, compensated by 36% birth.Item Acesso aberto (Open Access) Influência do tipo de superfície na densidade de ocorrência de raios sobre áreas da Amazônia Oriental(Universidade Federal do Pará, 2013-10-02) AARÃO JUNIOR, Raimundo Nonato Nascimento; SOUZA, José Ricardo Santos de; http://lattes.cnpq.br/2797414407717271The objective of this study was to analyze the relationship between the occurrence of lightning over different types of surfaces in selected areas situated in the eastern part of the Amazon Region during the period of July 2008 to November 2010. The studies were conducted in 8 areas, located in the State of Pará, Brazil. The studied areas feature a particular type of surface with homogeneous character. The lightning data were obtained from the database of the STARNET lightning detection network. Rainfall data were collected through 80 weather stations of the National Water Agency - ANA and the National Institute of Meteorology - INMET, while data classification of the types of surfaces were obtained from the Brazilian Institute of Geography and Statistics - IBGE. The results showed that different types of surfaces have contribute a significantly in occurrence frequency of lightning; lightning vary depending on seasonality and over the months during the year, with higher averages of correlated events with the period of maximum rainfall; the occurrence of lightning varies in time function, where both the rainy season and in the dry season the occurrences of these events tend to happen during the period between 14:00 UTC (15:00 UTC to dry season) and 22:00 UTC with major peaks observed in the rainy season. Also observed a lack of uniformity in the incident of lightning and precipitation on and between the same selected areas. Therefore, this study provides qualitative evidence of the importance of the types of surfaces and their influence over the observed occurrence of lightning.Item Acesso aberto (Open Access) Trocas turbulentas noturnas de CO2 entre a floresta de Uatumã, Amazonas, e a atmosfera(Universidade Federal do Pará, 2014-07-04) MAFRA, Ana Carolina Batista; SÁ, Leonardo Deane de Abreu; lattes.cnpq.br/0107976161469463; ARAÚJO, Alessandro Carioca de; lattes.cnpq.br/6188087583954899We study the nocturnal boundary layer - NBL above an area of primary tropical forest northeast of the state of Amazonas, the Sustainable Development Reserve of Uatumã, distant 15 km of the Uatumã River, located about 380 km northeast of the city of Manaus, Amazonas. It is intended to determine some of the characteristics of the NBL, particularly nocturnal turbulence regimes by identifying the differences related to vertical exchanges of CO2, according to the methodology proposed by Sun et al. (2012). Fast response data will be used for the atmospheric scalar and vector quantities, as CO2 concentration and wind speed, respectively. The methodology allows characterization of NBL in three regimes of dynamic stability: 1) weak turbulence, mean low wind speed; 2) strong turbulence, with high wind speed, and 3) intermittent turbulence events with "top -down ". From this characterization, we have investigated some of the main statistical characteristics of each turbulent regime. As would be expected, the turbulent fluxes of CO2 increases with the characteristic scale of turbulent velocity, VTKE, associated with turbulent kinetic energy measured above the forest canopy. The CO2 exchange increases considerably with the regime 2,with higher values of the mean wind speed, | V |, and with the occurrence of strong mixing in the atmospheric boundary layer, ABL, not predominantly generated by surface forcings .