Luiz Cláudio Gomes Pimentel

Caracterização do regime de vento em superfície na Região Metropolitana do Rio de Janeiro

This study deals with the characterization of surface wind regime in several sectors of Rio de Janeiro Metropolitan Region, and demonstrates the influence of daily wind cycle and the topographic aspects in the local wind circulations. For the evaluation of the wind pattern, it was used hourly data from different automatic surface meteorological stations. Afterward, these hourly data were organized in daily wind frequency. The results clearly showed that the modulation of local wind circulation follows the sea-land breeze system. It was remarkable the high percentage of calm wind conditions observed in the Afonsos weather station, which characterizes this station as a stagnation region influenced essentially by its local topographic features. Finally, this study provides large database on the direction and frequency of surface wind in the Rio de Janeiro Metropolitan Region, which could be used by the public authorities to improve their environmental management policy for the region.

Critérios de estabilidade atmosférica para a região da Central Nuclear Almirante Álvaro Alberto, Angra dos Reis - RJ

CRITERIA OF ATMOSPHERIC STABILITY FOR THE REGION AROUND THE NUCLEAR POWER PLANT ALMIRANTE ALVARO ALBERTO, ANGRA DOS REIS -RJ The atmospheric stability over the nuclear power plant Almirante Alvaro Alberto (CNAAA), Angra dos Reis - RJ, Brazil, was analyzed at climatological, seasonal, and daily scales. The climatologic analysis was based on the Pasquill-Gifford (P-G) for a long-term series of 26 years (1980 - 2006), while the seasonal/daily was performed using the Global Richardson number, RiB, and the Froude number, Fr, (case study 2002-2005). The Froude number was used for the regional flow characterization. According to the P-G criteria, the dominant classes were D, E and F (for diurnal and nocturnal periods). The most frequent sectors of wind direction were S, SSW, SSE in diurnal period and N, NNE, NNW and E in nocturnal. The highest wind velocities were observed for class D while the lowest values were observed for classes E and F, for both periods. The highest wind velocities were correlated to the occurrence of sea breeze. Based on RiB, the dominant stratification regime was stable (for 79% of the time), followed by unstable (17%) and neutral (4%). According to Fr, the flow around CNAAA was characterized by low wind velocities, strong stability and stagnant air. The Fr was lesser than 0.1 during 63% of the time, equal to 1 for 8% of the time and greater than 1.7 during 12% of the time. The criteria used in the determination of the stability and flow characteristics of this region indicated the lower dispersion capacity of the local atmosphere due to the prevalence of stable stratification regimes and blocking conditions.

Assessment of the unified analytical solution of the steady-state atmospheric diffusion equation for stable conditions

In this work, the performance of a unified formal analytical solution for the simulation of atmospheric diffusion problems under stable conditions is evaluated. The eigenquantities required by the formal analytical solution are obtained by solving numerically the associated eigenvalue problem based on a newly developed algorithm capable of being used in high orders and without missing eigenvalues. The performance of the formal analytical solution is evaluated by comparing the converged predicted results against the observed values in the stable runs of the Prairie Grass experiment as well as the simulated results available in the literature. It was found that the developed algorithm was efficient and that the convergence rate depends on the stability condition and the considered parametrizations for wind speed and turbulence. The comparisons among predicted and observed concentrations showed a good agreement and indicate that the considered dispersion formulations are appropriate to simulate dispersion under slightly to moderate atmospheric stable conditions.

Air quality photochemical study over Amazonia Area, Brazil

This work presents the results of a photochemical modelling system composed of MM5-SMOKE-CMAQ on Brazilian Amazonia area, been a pioneered implementation task. These results focus on the biogenic and biomass burning emissions and the impact of these emissions on regional air quality. Global and local anthropogenic emissions data, satellite-derived biomass burning inventories, and biogenic emissions calculated with MEGAN model were used to estimate emissions over the domain. The goal is the development of air quality model input data for CMAQ. Results are consistent with O 3 formation theory and CO hotspot concentration matches with the geographic area of biomass burning.

Influência dos parâmetros de configuração do modelo CALMET sobre a simulação da circulação atmosférica na região metropolitana do Rio de Janeiro

The aim of this study is to analyze the effects of configuration parameters of the CALMET model on the simulation of atmospheric circulation over the surface at Air basins I and III on the Metropolitan Region of Rio de Janeiro (RMRJ). The study was conducted in a period when the RMRJ was under a high-pressure acting system, which not strongly influenced the local circulation over the region. The joint analysis of all results show that the best configuration for wind field simulations at the RMRJ, with the combined MM5/CALMET modeling is obtained using the value of 10 km for the TERRAD parameter and between 7 and 10 km for the influence radius.

MODELAGEM DA CONCENTRAÇÃO DE POLUENTES NA BACIA AÉREA III VIA MODELO AERMOD CONSIDERANDO PROCESSOS DE DEPOSIÇÃO

Modelagem da concentracao de poluentes na bacia aerea IIIvia modelo AERMOD considerando processos de deposicao

Vulnerability Factors for Emergency Planning of the Angra dos Reis Nuclear Power Complex - RJ

O complexo nuclear de Angra dos Reis, no litoral sul do estado do Rio de Janeiro, tem no seu espaco geografico diferentes aspectos que integram a dinâmica ambiental de sua area de influencia, onde os fatores geologicos, meteorologicos e demograficos caracterizam a regiao como um ambiente complexo, sobretudo com a projecao de acoes de emergencia a partir de um evento acidental, especialmente sob o ponto de vista da evacuacao da populacao nas areas impactadas, apresentando particularidades que contribuem no sentido de atuar como impacto negativo em situacoes de emergencia, principalmente na fase de resposta a um possivel acidente. Com o apoio de sistemas de informacao geografica (SIG), foram feitas analises entre a suscetibilidade aos deslizamentos e suas ocorrencias (inventario dos anos 2007-2011), associando o regime de chuvas e a densidade populacional, aspectos que demostram a vulnerabilidade da regiao, principalmente ao longo da rodovia BR-101, com potencial de inviabilizar as rotas de fuga em situacoes criticas. A analise integrada destes fatores apontou que, em conjunto, tais elementos sao importantes gargalos para as situacoes de emergencia na regiao, devendo ser incluidos como fatores criticos a serem analisados no sentido de contribuir para subsidiar acoes e diretrizes que devem ser aplicadas no planejamento da emergencia local.

Supportive elements to the decision-making process in the emergency planning of the Angra dos Reis Nuclear Power Complex, Brazil

Accidents in nuclear power plants are problems of great complexity, mainly due to their consequences, such as the population evacuation from the enterprise influence area. The decision-making and emergency plans must be well articulated and require good local geographic space knowledge and the interactions of their environments. This study is a contribution to the emergency plans for the Almirante Álvaro Alberto Nuclear Power Plant, currently the only nuclear complex in Brazil, located in Angra dos Reis, Rio de Janeiro. The study confirmed the region’s main geoenvironmental aspects as winds and rainfall, landslides and population density were evaluated as important elements in the local emergency process. Their integrated analysis supported scenario identification and critical regional points and highlighted population evacuation escape routes. These important results characterized the support to local emergency management actions and guidelines. Furthermore, the geographic information systems was configured as an integrated spatial and temporal analysis platform to associate meteorological, geological/geomorphological and socio-economic data, playing a key role to support the evacuation planning in the event of nuclear power plant accidents.

Análise comparativa da concentração de dióxido de enxofre via modelos regulatórios AERMOD e CALPUFF e monitoramento próximo às fontes de emissão da bacia aérea III - RMRJ

The Rio de Janeiro Metropolitan Region (RJMR) can be characterized as a region affected by distinct and complex mechanisms concerning atmospheric pollutants dispersion and it has been submitted to great transformations in atmospheric emissions configuration. Therefore an evaluation of the current tools, indicated by the local environment agencies for regulatory modeling to obtain new environmental licenses becomes important mainly due to recently discussions by the scientific community concerning modeling practices. In the present context, the air quality regulatory models AERMOD and CALPUFF had their performance evaluated using a typical near field modeling configuration applied to the RJMR. The statistical results showed a better performance of the CALPUFF model than the AERMOD model when applied to the Air Basin III. CALPUFF model shows a more conservative simulation of the problem, with higher concentrations values, while the use of AERMOD model resulted in lower concentrations values. For all evaluation criteria CALPUFF demonstrated to be more realistic in the estimation of the sulfur dioxide concentration when submitted to local dispersions conditions at the studied period, suggesting it is adequate to the RJMR Air Basin III air quality management.

Análise do Desempenho dos Modelos MM5 e WRF na Simulação da Temperatura do Ar em Superfície na RMRJ

The urbanization dynamics in big cities produces a highly degraded environment with serious damages to human life quality. The Metropolitan Region of Rio de Janeiro (MRRJ) have been exposed to several anthropogenic activities that produces environmental problems, for example: the intense modification of soil cover behind the phenomenon of Urban Heat Island (UHI). This study evaluates the performance of MM5 and WRF meteorological models to simulate the near surface air temperature variable in MRRJ. The model results are compared with observational data using statistical indexes to a period of UHI occurrence. The evaluation uses the daily cycle of air temperature and statistical indexes between simulated and observed data. The result shows a satisfactory performance of both models to reproduce the daily cycle of near surface air temperature for the entire study period. A slightly tendency to underestimate the maximum temperatures were observed on simulated results, as well as an overestimate of minimum temperatures. Analyzing the statistical indexes, a similar performance between the MM5 and WRF were presented according the observed data from SBGL, SBAF, SBJR, and SBSC stations. The largest deviations between predicted and observed results occurred to SBRJ station. The analysis of temporal variation and statistical indices showed that MM5 and WRF meteorological models are able to represent the near surface air temperature both to spatial distribution as to temporal variation.