Publicações

Thunderstorms are part of the complex and interactive processes that form the climate. Its variability can arise from a number of factors, some internal others external to the climate system. In consequence, our ability to predict future climate changes in the thunderstorm activity depends on a better understanding of the climate system as a whole and the external factors that could be involved such as volcanic eruptions and solar variations, as well as human-induced changes in atmospheric composition. Such an understanding can only be achieved through a greater ability to document and explain observed past variations. The study of thunderstorm changes offered the opportunity to gain a better understanding of atmospheric electricity. Also, the possibility that, as the global warming continues to evolve, increasing evidence of thunderstorm changes are found, will help to understanding the climate system, since thunderstorms as ice factories play a key role in the vertical redistributors of the most important greenhouse substance, the water vapor (Williams and Sátori, 2004). At the present time, no direct or even indirect evidences of global increase in the thunderstorm activity exist in response to the mean global temperature increase, although positive trends are observed in specific areas where larger temperature increases than the global increase are observed (Pinto and Pinto, 2008; Williams, 2009, Pinto, 2009). In the tropics the current trend in global warming is less by a factor of four (0.1 °C per decade) than at higher latitudes (0.4 °C per decade), particularly in the Northern Hemisphere (Trenberth et al., 2007). This aspect tends to minimize any kind of response of global thunderstorm activity to global warming, since most thunderstorms on Earth occur in the tropical region (Pinto, 2009). In this paper the variation of the thunderstorm activity in the city of São Paulo, Southeast Brazil, are further investigated with respect to changes in the surface air temperature in the last 60 years (since 1951) at the 30-year and monthly time scales. While the 30-year period was chosen following the period adopted by the World Meteorological Organization (WMO) to estimate long term climate variations, the monthly variation can be used to predict the future activity with more confidence than the simple annual variation.

This work presents the state of art of the studies regarding impact of extreme climate events (like heavy floods and severe droughts) in the Amazon basin in the livelihood of local riverine population inhabitants of the region. It draws from fieldwork experiences carried out in Flona do Tapajós, Lower Amazon, Silves municipality, Central Amazon, and Mamirauá Sustainable Development Reserve, Upper Amazon Basin. It collected local accounts about how the local communities perceive interannual variability that is increasing because of extreme climatic events. Inasmuch, it assessed the impact of severe drought in 2005 and 2010 on their livelihood and the heavy flood of 2006 and 2009, touch on adaptation strategies developed by locals to overcome these extreme events, especially regarding its impact on natural resources management at the same time investigating the public policy in place to deal with disasters in the region. As a conclusion, this work points out some gaps on the scientific and policymaking strategies on the region as well as some guidance of how to move forward with science- policy agenda interface aiming towards sustainability, food security and socioeconomic wellbeing of Amazon population face global environmental change.

The Brazilian northeast is a region characterized by a semi-arid climate, with precipitation highly variable spatially and in time, with high atmospheric evaporation demand. Model simulation, associating future climate change to anthropogenic use of the soil, suggest an even drier climate in the region in the future, with serious effects in the hydrological and nutrient balances. The intensification of dry climate and extreme events (drought spells or intense precipitation) has the potential to impact significantly the predicted 75millions people leaving in the region by the middle of the century. As example, some recent studies indicate that, considering the A2 IPCC scenario, the region might loose 50% in its agricultural potential by 2050. The aim of this work is to present a suit of studies that are being conduct in the Brazilian Northeast looking at land use mapping to support modeling (IBIS, CENTURY) and field experimental activities on nutrient cycling, agricultural production, emissions of green house gases, climate change scenarios and food security. Vulnerability and adaptation are being accessed envisioning providing subside for public policies in the region for agriculture production, water use and land use change planning.

There are a wide range of challenges arising from global changes such as increasing globalization and future technological, economic and behavioral changes. Rapid changes, uncertainty and growing risks, are resulting in a great number of limitations to agricultural policy and practice that reveal the inadequacies for their long-term sustainability. Thus, the challenges that impact on agri-food systems require new solutions, such as adoption of new energy sources, new forms of information, communication and technology, new pharmaceuticals and medical knowledge, and also a shift in consumer behavior. The application of these new solutions, may result on the emergence of agri-food systems with new features, very different from what we know today (FRESH, 2009), such as the return of urban and peri-urban agriculture and its multifunctionality in political discourses, social movements and in real lives of cities dwellers all around the world. Noting that, new forms of inquiry are necessary, but for that, it is necessary to have a new perspective on the drivers of changes, and a careful look on the culture or cultural dimension in which the agri-food systems and its actors are inserted. Thus, this essay intends to highlight some topics that are relevant to the discussion on how consumption, stimulated by the market, and the consumers, through their choices, can influence the agri-food systems and be a major factor on political decision choices that could affect the future of human food security.

In Brazil, the recent urbanization process has acquired a characteristic of expansion that differs from the model highly concentrated in metropolitan areas, expanding in number and size, the medium-sized cities with the same patterns of urbanization than metropolitan areas (CARVALHO, 2003). And as long food production spaces are being reduced as urbanization rises, there is also an increase on demand for food to urban dwellers, dependents on food market (RUAF, 2009) and vulnerable to supply and prices fluctuations. Knowing that global changes are not equal for all, or occur in the same way throughout the globe (Hulme, 2009), impacting most the more vulnerable ones, it is necessary to better understand the connections between urbanized space, food production, environment and people within urban systems. In this sense, this work aimed to understand the ecological dimension of urban agriculture (UA) in intra and periurban areas of the main district of Juiz de Fora, Minas Gerais State, Brazil. The research found 179 areas of UA occurrence, classified as: Social Projects of Municipal Schools, Institutions (public, religious, welfare and medical units), Commercial Productive Areas and Productive Backyards (in one neighborhood – Monte Castelo). Semi-structured interviews and field observations were carried out in a total of 77 areas. Empirically, it was possible to investigate the interactions between actors and environment. The results show a number of 173 cultivated plant species in the areas of UA, many of them, native from Brazil or Latin America, and also 69 species of wild animals that benefit from cultivated areas. The survey also demonstrates the importance of those areas of UA to those involved, for the conservation of natural resources and biodiversity, for the maintenance of traditional knowledge and that it could be considered as a valuable environmental service provision tool for cities’ sustainability.

In Brazil, the Human Right to Adequate Food was institutionalized on January 2010, when adequate feed was incorporated within the Citizens Social Rights as part of the Brazilian Federal Constitution. Despite that, the access to adequate food necessary to guarantee and promote such rights has been limited by consequences of Social-economic and Environmental Global Changes (ERICKSSEN, 2008; EAKIN, 2010). Cities’ expansion in size and number, and population growth concentrated in urban areas can reduce viable spaces near cities to produce fresh food to respond to the rising demand for food by urban consumers (FAO-FCIT & RUAF, 2009). Vegetables are vital food for a healthy human diet (Tofanelli, 2007), and their long route within the market chain represents a set-back step between production and consumption, resulting in great losses due to high perishability of these products (35% of total Brazilian production is lost before consumption), raising prices (Tofanelli, 2007) and influencing negatively on the access to food. In this context, the identification of areas close to consumption centers and suitable for vegetables production, can subsidize the formulation of public policies, and be part of a core adaptation mechanism to achieve food security of urban population in a near future. Thus, this work aimed to apply GIS techniques to build a map of potential areas suitable to crop horticulture in the micro region of São José dos Campos, São Paulo, Brazil. We adopted biophysical, infrastructure and spatial zoning data (e.g. soil types, slope, river and road networks, conservation reserves and urban areas) and spatial analysis techniques available in SPRING 4.3.3 software. The results provide a rich material to support stakeholders´ discussion about potential areas where horticulture could be developed and/or should be tackled as priority areas in a near future to improve the nutritional security of the citizens of this region

Este trabalho tem como objetivo a conclusão do projeto de iniciação científica proposto, o qual consiste numa análise temporal a cerca da evolução da cultura de eucalipto sobre o Vale do Paraíba Paulista e suas consequências para as bacias hidrográficas do local. A primeira fase do projeto foi organizada na obtenção de imagens de satélite para posterior análise e classificação de uso e cobertura do solo. Foram selecionadas imagens do satélite Landsat 5, sensor TM, nas bandas 3, 4 e 5 dos anos de 1995 e 2010; nas órbitas / ponto: 218/76 e 219/76. Depois de selecionadas, as imagens foram devidamente processadas e classificadas através do Sistema de Informações Geográficas (SIG) SPRING. Depois, foi realizada a divisão da imagem em grandes classes (não floresta, transição, floresta) através do NDVI – Índice de Vegetação Normalizado pela Diferença. Esta fase teve por objetivo facilitar a classificação da área de estudo. O método escolhido para classificação foi a classificação não supervisionada das imagens, em que os grandes grupos selecionados foram segmentados e depois classificados através do classificador automático IsoSeg. Terminada esta etapa a imagens foram editadas e remapeadas, e ao final do processo foram obtidas as cartas de uso e cobertura do solo do Vale do Paraíba Paulista nos anos em questão. A segunda fase consistiu na obtenção de dados SRTM (Shuttle Radar Topography Mission), que serviram à geração de um MNT (Modelo Numérico de Terreno). A utilização do aplicativo TerraHidro permite, através do algoritmo HAND Height Above Nearest Drainage , a divisão do território em 3 classes topológicas: Baixio, Vertente e Topo de Morro; as quais foram cruzadas com as áreas de silviculturas obtidas através da classificação de uso e cobertura do solo realizada para os dois anos (1995 e 2010). A análise das duas classificações verificou um aumento da área coberta por silvicultura da ordem de 42 mil hectares para 60 mil hectares. Mesmo com o aumento, 47% do plantio continuou nas vertentes. O plantio em topos de morro aumentou de 25% para 27% do total, enquanto o plantio em áreas de baixio reduziu de 27% para 25% do total.

The Brazilian Total Lightning Network (BrasilDAT) combines advanced lightning detection technologies with modern electronics and already covers 11 States of Brazil. The network is composed of 48 EarthNetworks Lightning Sensors (ENLS), each of them with a GPS-based timing circuit, a digital signal processor (DSP) and onboard storage and internet communication equipment. The ENLS is a wideband system with detection frequency ranging from 1Hz to 12MHz. The wide frequency range enables the sensor to not only detect cloud-toground (CG) strokes, but also intra-cloud (IC) pulses. The sensor records whole waveforms of each event and sends them back, in compressed data packets, to the central processor. Instead of using only the peak values, the whole waveforms are used in locating the events and differentiating between IC and CG discharges. Sophisticated digital signal processing technologies are employed on the server side to ensure high-quality detections and to eliminate false locations. This paper presents some preliminary results of two severe storms in Southeastern Brazil that were tracked by BrasilDAT showing the spatial and temporal evolution of IC and CG discharges compared to radar, satellite images and numerical model products. Those results showed the potential of total lightning information for CG lightning warning purposes.

Este trabalho tem como objetivo a continuidade o estudo e o aperfeiçoamento dos algoritmos para a determinação da cobertura efetiva de nuvens em imagens do satélite geoestacionário GOES. As nuvens apresentam importância no controle da temperatura na superfície uma vez que está relacionada com a capacidade de reflexão da energia solar. As nuvens são o fator principal de modulação da irradiação solar incidente na superfície e desempenham um papel fundamental no balanço enérgico do planeta. Além disso, a observação das nuvens também são relevantes para observar e obter informações sobre fenômenos meteorológicos como furações, ciclones, frentes frias. Atualmente, a utilização de satélites artificiais, vem sendo cada vez mais explorada na utilização em pesquisas cientificas, tendo como grande foco as áreas meteorológicas. A observação de cobertura de nuvens por meio de análise de imagens de satélite vem sendo bastante investigada nos últimos anos. A radiação solar fornece energia para todos os seres vivos e para alguns sistemas de sensores (passivos) utilizados para geração de eletricidade e aquecimento de água. A cobertura efetiva de nuvens é utilizada para alimentar o modelo de transferência radiativa BRASIL-SR utilizado para o mapeamento de recursos de energia solar no território brasileiro. O modelo BRASIL-SR foi desenvolvido no INPE com o apoio da Universidade Federal de Santa Catarina (UFSC) e do Instituto de Pesquisa GKSS/Alemanha. O modelo BRASIL-SR utiliza informações climatológicas de temperatura, visibilidade atmosférica, albedo de superfície e umidade relativa em conjunto com a cobertura efetiva de nuvens para parametrizar os processos radiativos que ocorrem na atmosfera. Dessa forma, este trabalho visa o desenvolvimento de uma base de dados mais confiável para alimentar o modelo de transferência radiativa permitindo assim a obtenção de estimativas de irradiação solar incidente na superfície com desvios menores quando comparados aos valores observados em experimentos de campo. Neste período, foram desenvolvidas as competências para desenvolvimento de algoritmos utilizando o pacote computacional MATLAB para o processamento de imagens do satélite GOES. Os primeiros resultados estão sendo obtidos e uma comparação entre um método alternativo utilizando percentis em substituição de valores máximos e mínimos mensais está sendo utilizado para a composição de imagens de céu claro e encoberto. O Instituto Nacional de Meteorologia (INMET) é um órgão governamental que possui dados sobre o clima em todo território brasileiro. O banco de dados do INMET será utilizado para comparar e ajudar na validação de dados de cobertura efetiva de nuvens do satélite geoestacionário GOES.