José Ricardo de Almeida França

Urban climate and clues of heat island events in the metropolitan area of Rio de Janeiro

This paper aims to map the thermal field in the metropolitan region of Rio de Janeiro (MARJ) considering the atmospheric characteristics and the land use that contribute to understanding the urban heat island. Three thermal maps are defined through the use of Landsat5-TM satellite images for three winter events chosen for the decades of 1980, 1990, and 2000, respectively. The results reveal a concentration of warmer cores in urban central areas as well as some local warmer areas in suburban region. Sites with lower temperatures correspond to vegetated areas which are away from the central part of the MARJ, including points of suburban areas. This work emphasizes the importance of the combined analysis of surface temperature with land use and atmospheric conditions, depicting a distinct pattern of heat islands for tropical climate.

Um Estudo do Fenômeno da Ilha de Calor Urbana na Região Metropolitana do Rio de Janeiro (RMRJ)

The main objective of this study is analyze the field of Surface Temperature (TS) of the Metropolitan Region of Rio de Janeiro (RMRJ) and its relation to land use. The analysis was based on vegetation index NDVI and TS values obtained from NOAA - 14 and 18 images covering the 2005 to 2010 years. The Maximum Value Composite method was used to generate of TS and NDVI monthly maps and also for all data period. The different statistical parameters (e.g. correlation and determination coefficients, linear regression and standard deviation) were calculated to determine the relationship between TS and NDVI. The TS monthly values for NOAA - 14 satellite shown to be high in the early morning, although slightly lower than NOAA - 18 satellite due to the different times of passage. It was observed that Urban Heat Island (ICU) phenomenon operates throughout the year, especially in the eastern portion of the city and in the Baixada Fluminense cities. The inverse relationship between TS and NDVI was observed mainly in the autumn and winter months with the highest correlation and determination coefficients. However, this is not observed in the summer months because the heating effect of macroscale (weather effects) overlaps with land use.

Comparação das Propriedades Microfísicas de Diferentes Tipos de Nuvens em Duas Regiões Tropicais com Ecossistemas Distintos Usando Dados do Satélite CloudSat

The approach used in this works methodology looks to represent the average microphysical structure of different types of clouds formed in two different ecosystems. The selected regions were located in the Midwest of Brazil (coordinates: 12-18 ° S and 46-58 ° W) and the South Atlantic Ocean (coordinates: 12-25 ° S and 9-30 ° W). In order to accomplish the proposed goal, data from CloudSat satellite from a period of approximately five years are used (from June 2006 to April 2011). The results show that there is little variation in microphysical structure between continental and maritime clouds in the studied regions. The mean droplet (ice particle) effective radius obtained in all the cloud types analyzed was 12.4 I¼m (71.9 I¼m) for maritime clouds and 11.0 I¼m (72.9 I¼m) for continental clouds. Particle size distribution (concentration as a function of size) was the most efficient parameter to distinguish cloud types, making it possible to identify particularities of each type. The results showed that even in the period with the highest concentration of aerosols observed in the Central-West region of Brazil (spring), there is a significant difference in the cloud particle size distribution in the regions studied. These results indicate that other external agents (besides the total concentration of aerosol integrated in the atmospheric column) are acting more significantly to modulate the particles distribution within the clouds in the Central-W est region.

Estimation of the urban heat island in the Metropolitan Area of Rio de Janeiro - Brazil

This study aims to map the urban heat island in the metropolitan area of Rio de Janeiro (MARJ) using remote sensing data to derive land use maps and land-surface temperature (LST) fields based on Landsat data. The LST difference between urban and vegetation and the temporal evolution of LST were verified based on the Studentss t statistical test conducted at the 5% level. Obtained results indicate that LST has increased by approximately 2.0 °C over the last decade and that urban heat island has increased from 4.4 to 6.1 °C.

Estudo da Ilha de Calor na Região Metropolitana do Rio de Janeiro Usando Dados do MODIS

The Metropolitan Area of Rio de Janeiro (MARJ) presents a number of environmental problems, among them, the occurrence of Urban Heat Islands (UHI). This paper examines the characteristics of the UHI in the MARJ. For such, 8-days compositions data of Land Surface Temperature (LST), during the period from January 2003 to December 2010, generated by the MODIS (Moderate-resolution Imaging Spectroradiometer) sensor, aboard the Terra and Aqua satellites were used. The data analysis was done by calculating the average LST gathering data for the satellites pass over the seasons, so it could be analyzed more clearly, without cloud contamination. It was observed, some zones presented temperatures close to 50oC during the spring and summer. Throughout the autumn and winter the average reached 40 o C over most of the study area. During the spring, a 25oC temperature range was registered between areas with different urbanization levels. In the summer the amplitude was 20oC between the same areas. In autumn the difference was 15oC and in winter, 10oC.

Balanço de Radiação em Superfície na Região Metropolitana do rio de janeiro

The radiation budget at the surface of the Metropolitan Region of Rio de Janeiro was obtained from measurements collected on the radiometric platform located...

Characterization of the Physical Structure of Clouds over Different Ecosystems of South America Using MODIS Cloud Products Data

Clouds play an extremely important role in the physical processes of the atmosphere, in different space and time scales. They affect the energy budget in all atmosphere levels by interacting with solar and earth radiation. The characteristics of clouds that influence the energy budget can be quantified by some physical parameters which classify each cloud type. Hence, it’s possible to use these parameters in numerical modeling in order to improve model diagnosis and, consequently, prognosis. The most practical way to obtain cloud information is through remote sensing, since direct access is not easy to achieve. This paper uses data from MODIS sensor (from when it became available in 2000 on TERRA platform until nowadays) to retrieve cloud properties and analyze two cases for six distinct regions in South America and compare the microphysical structure of stratiform cloud types in each of these regions. The analyzed parameters on this paper are Cloud Effective Particle Radius and Optical Thickness. Some re...