Navegando por Assunto "Modelagem climática"

Agora exibindo 1 - 4 de 4

Acesso aberto (Open Access)
Modelagem climática regional durante dois anos de extremos de precipitação sobre o estado do Amapá: teste de sensibilidade aos esquemas convectivos
(2011-12) NEVES, Daniel Gonçalves das; CUNHA, Alan Cavalcanti da; SOUZA, Everaldo Barreiros de; BARRETO, Naurinete Jesus da Costa
This study shows an assessment of the seasonal forecast model RegCM3 in two extreme events of precipitation for the years 2006 and 2007. For the analysis a 1° x 1º km horizontal resolution was used and validated with 30 x 15 points of latitude x longitude for the region of the State of Amapa. The presented results are for the comparison between simulated and observed seasonal precipitation in the quarter (MAM). In general, the results showed that using the scale reduction technique to predict the seasonal rainfall, a good performance in simulating the variability of rainfall on a regional scale is obtained. However, errors in the precipitation amount and on some maximum position were observed when compared with the observed data. The wet bias was prevalent in the humid coastal region and the dry bias in the south-southeast, west and center with a strong persistence in the Southeast. Regions with precipitation values close to the observed ones were not very evident.
Acesso aberto (Open Access)
Modelo OLAM (ocean-land-atmosphere-model): descrição, aplicações, e perspectivas
(2009-06) SILVA, Renato Ramos da; DIAS, Pedro Leite Silva; MOREIRA, Demerval Soares; SOUZA, Everaldo Barreiros de
The OLAM model was developed to extend the capability to represent the global and regional scale phenomena simultaneously. The model presents innovations regarding to the dynamic processes, grid configuration, memory structure, and numerical technique solutions for the prognostics equations. The Navier-Stokes equations are solved using the finite volume technique that conserves mass, momentum, and energy. In this study the OLAM model is described, and results are presented for its application on the climate mode to simulate the monthly prediction of precipitation for South America and numerical weather prediction. The results show that the model is able to represent reasonable the large scale meteorological processes. In general, its performance improves when grids of greater resolution is adopted, for which significant improvements are observed for the monthly precipitation simulation estimates as for the numerical weather prediction.
Acesso aberto (Open Access)
Níveis de resiliência ecológica de quelônios continentais da Amazônia Legal
(Universidade Federal do Pará, 2024-12-23) GUIMARÃES, Lívia Isadora de Almeida; SILVA, José Francisco Berrêdo Reis da; http://lattes.cnpq.br/1338038101910673; HTTPS://ORCID.ORG/0000-0002-8590-2462; TOLEDO, Peter Mann de; http://lattes.cnpq.br/3990234183124986
Continental chelonians, especially the Amazonian ones, are among the groups which most demand new researches and integrated studies, whether in the systematic or ecological scope, whose knowledge helps in their preservation, as well as ecosystem and environmental services performed. Therefore, the present work aims to analyze the levels of climate resilience of continental species in the Legal Amazon, via correlation/interdisciplinarity between climate models and anthropogenic pressure with geochemical proxies, more specifically isotopes of carbon and nitrogen, with results that enable interpretations more precise information on climatic and isotopic refuges (isoscapes), as well as additional information related to trophic chains. Until then, climate models were developed, with simulations referring to Representative Concentration Pathways (or RCPs) and Shared Socioeconomic Pathways (or SSPs) for ten chelonian species, given their sufficient number of recorded observations and coordinates: Chelus fimbriata; Mesoclemmys gibba; Phrynops geoffroanus; Platemys platycephala; Podocnemis expands; Podocnemis unifilis; Rhinoclemmys punctularia; Kinosternon scorpioides, Chelonioidis carbonaria and Chelonoidis denticulata. Such coordinates were intercrossed with four environmental variables from the Worldclim digital platform, selected according level of influence on the species distribution, reported in the literature, as well as reduced inter-correlation. These procedures were performed by Rstudio software, through the Biomod2 package, which reunites a set of algorithms whose mathematics allowed the development of rasters, with informations of climatic suitability inherent to each species. So far, P. expansa, P. unifilis and, above all, Ch. denticulata, are considered the most threatened of population reduction, while Ph. geoffroannus and K. scorpioides projections have shown less climate vulnerability. This parameter tends to be maintained in future circumstances, even with anthropogenic interference. The other species also present certain levels of vulnerability, which are more limited when compared to Ch. denticulata e P. unifilis levels. Confrontation of projections with isotopic signatures from nitrogen and carbon, collected from bone tissues of specimens deposited at the Instituto Nacional de Pesquisas Amazônicas (INPA, Manaus/AM) and Museu Paraense Emílio Goeldi (MPEG, Belém /PA). with climate models and anthropogenic influence, tend to reinforce politics to preserve species and their niches, as a strategy to maintain regional biodiversity.
Acesso aberto (Open Access)
Sazonalidade da precipitação para a Amazônia usando o modelo REGCM3: avaliando apenas a forçante do Atlântico Equatorial
(2012-12) FERREIRA, Wesley Rodrigues Santos; VITORINO, Maria Isabel; SOUZA, Everaldo Barreiros de; CARMO, Alexandre Melo Casseb do
The present study tries to bring a new perspective of the Equatorial Atlantic Ocean importance on seasonal pattern, during the summer and fall on the Amazon region. It contributes in a different way for studies in the area of climate modeling and variability of rainfall over the region. For this study, we used the model RegCM3 with Grell convection scheme, applying the donwscaling technique and using, as initial condition, NCEP/NCAR reanalysis data. After the simulations statistical method of the Bias was applied to evaluate how the accurately the model can reproduce the reanalysis seasonal rainfall. In a first analysis, it appears that the model is sensitive to FS or SAZC occurrences, as well as approaching the dynamics of the tropics and extratropics. The results suggest that the low resolution and the Grell parameterization are the main factors for inadequate quality of the simulations. Although the Grell scheme is suitable for areas with intense convection and strong vertical movements, an adjustment to the physical characteristics of the region is required. This study contributed to the improvement of regional climate models for the Amazon region, considering the contribution of ocean-atmosphere processes, during the summer and autumn in the southern hemisphere.