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The aim of this investigation is to analyze the phenomenology of positive and negative (stepped and dart) leaders observed in natural lightning from digital high-speed video recordings. For that intent we have used four different high-speed cameras operating at frame rates ranging from 1000 or 11,800 frames per second in addition to data from lightning locating systems (BrasilDat and NLDN). All the recordings were GPS time-stamped in order to avoid ambiguities in the analysis, allowing us to estimate the peak current of and the distance to each flash that was detected by one of the lightning locating systems. The data collection was done at different sites in south and southeastern of Brazil, southern Arizona and South Dakota, USA. A total of 62 negative stepped leaders, 76 negative dart leaders and 29 positive leaders were recorded and analyzed. From these data it was possible to calculate the two-dimensional speed of each observed leader, allowing us to obtain its statistical distribution and evaluate whether or not it is related to other characteristics of the associated flash. In the analyzed dataset, the speeds of positive leaders and negative dart leaders follow a lognormal distribution at the 0.05 level (according to the Shapiro-Wilk test). We have also analyzed how the two-dimensional leader speeds change as they approach ground through two different methodologies. The speed of positive leaders showed a clear tendency to increase while negative dart leaders tend to become slower as they approach ground. Negative stepped leaders, on the other hand, can either accelerate as they get closer to ground or present an irregular development (with no clear tendency) throughout their entire development. For all the three leader types no correlation has been found between the return stroke peak current and the average speed of the leader responsible for its initiation. We did find, however, that dart leaders preceded by longer interstroke intervals cannot present speeds of the order of 107 m s- 1. Finally, we have analyzed the impact of recoil activity during positive leaders over their average speed and the return stroke peak current. Even though the analysis considering the leader speed was not conclusive it was possible to show that there is no apparent minimum or maximum peak current value for return strokes preceded by leaders with or without recoil activity (considering the most common range of values in literature, 20-80 kA).

Agriculture, deforestation, greenhouse gas emissions and local/regional climate change have been closely intertwined in Brazil. Recent studies show that this relationship has been changing since the mid 2000s, with the burgeoning intensification and commoditization of Brazilian agriculture. On one hand, this accrues considerable environmental dividends including a pronounced reduction in deforestation (which is becoming decoupled from agricultural production), resulting in a decrease of <40% in nationwide greenhouse gas emissions since 2005, and a potential cooling of the climate at the local scale. On the other hand, these changes in the land-use system further reinforce the long-established inequality in land ownership, contributing to rural-urban migration that ultimately fuels haphazard expansion of urban areas. We argue that strong enforcement of sector-oriented policies and solving long-standing land tenure problems, rather than simply waiting for market self-regulation, are key steps to buffer the detrimental effects of agricultural intensification at the forefront of a sustainable pathway for land use in Brazil.

The meteorological characteristics of the drought of 2005 in Amazonia, one of the most severe in the last 100 years were assessed using a suite of seven regional models obtained from the CLARIS LPB project. The models were forced with the ERA-Interim reanalyses as boundary conditions. We used a combination of rainfall and temperature observations and the low-level circulation and evaporation fields from the reanalyses to determine the climatic and meteorological characteristics of this particular drought. The models reproduce in some degree the observed annual cycle of precipitation and the geographical distribution of negative rainfall anomalies during the summer months of 2005. With respect to the evolution of rainfall during 2004-2006, some of the models were able to simulate the negative rainfall departures during early summer of 2005 (December 2004 to February 2005). The interannual variability of rainfall anomalies for both austral summer and fall over northern and southern Amazonia show a large spread among models, with some of them capable of reproducing the 2005 observed negative rainfall departures (four out of seven models in southern Amazonia during DJF). In comparison, all models simulated the observed southern Amazonia negative rainfall and positive air temperature anomalies during the El Nino-related drought in 1998. The spatial structure of the simulated rainfall and temperature anomalies in DJF and MAM 2005 shows biases that are different among models. While some models simulated the observed negative rainfall anomalies over parts of western and southern Amazonia during DJF, others simulated positive rainfall departures over central Amazonia. The simulated circulation patterns indicate a weaker northeasterly flow from the tropical North Atlantic into Amazonia, and reduced flows from southern Amazonia into the La Plata basin in DJF, which is consistent with observations. In general, we can say that in some degree the regional models are able to capture the response to the forcing from the tropical Atlantic during the drought of 2005 in Amazonia. Moreover, extreme climatic conditions in response to anomalous low-level circulation features are also well captured, since the boundary conditions come from reanalysis and the models are largely constrained by the information provided at the boundaries. The analysis of the 2005 drought suggests that when the forcing leading to extreme anomalous conditions is associated with both local and non-local mechanisms (soil moisture feedbacks and remote SST anomalies, respectively) the models are not fully capable of representing these feedbacks and hence, the associated anomalies. The reason may be a deficient reproduction of the land-atmosphere interactions.

Two simultaneous extreme events affected tropical South America to the east of the Andes during the austral summer and fall of 2012: a severe drought in Northeast Brazil and intense rainfall and floods in Amazonia, both considered records for the last 50 years. Changes in atmospheric circulation and rainfall were consistent with the notion of an active role of colder-than-normal surface waters in the equatorial Pacific, with above-normal upward motion and rainfall in western Amazonia and increased subsidence over Northeast Brazil. Atmospheric circulation and soil moisture anomalies in the region contributed to an intensified transport of Atlantic moisture into the western part of Amazonia then turning southward to the southern Amazonia region, where the Chaco low was intensified. This was favored by the intensification of subtropical high pressure over the region, associated with an anomalously intense and northward-displaced Atlantic high over a relatively colder subtropical South Atlantic Ocean. This pattern observed in 2012 was not found during other wet years in Amazonia such as 1989, 1999, and 2009. This suggests La Nina as the main cause of the abundant rainfall in western Amazonia from October to December, with wet conditions starting earlier and remaining until March 2012, mostly in northwestern Amazonia. The anomalously high river levels during the following May-July were a consequence of this early and abundant rainy season during the previous summer. In Northeast Brazil, dry conditions started to appear in December 2011 in the northern sector and then extended to the entire region by the peak of the rainy season of February-May 2012.

The National Program for Production and Use of Biodiesel (PNPB), launched in Brazil, is based on the diversification of its feedstock and social inclusion. Among the various oilseeds, palm was identified as the ideal one for the Northern region. However, the participation of palm is still not representative in the Brazilian biodiesel matrix. The key industrial challenges to promote oil palm in the biodiesel sector (as well as surpass them) are represented in the data presented herein. The current level of production is not enough to meet the industry’s needs. The use of this oil appears to be a viable possibility in the medium-term. However technological limitations, infrastructure, transaction costs and high investments are pivotal bottlenecks to promote palm in the biodiesel chain. Concerning social promotion, there are not enough results yet. The prolonged process of economic marginalization, which family farmers have undergone in the Northern region, results in companies having to engage in social activities that aim at deeper cultural changes.

The response of the global climate system to atmospheric CO2 concentration increase in time is scrutinized employing the Brazilian Climate Model (BESM-OA2.3). Through the achievement of over two thousand years of coupled model integrations in ensemble mode, it is shown that the model simulates the signal of recent changes of global climate trends, depicting a steady atmospheric and oceanic temperature increase and corresponding marine ice retreat. The model simulations encompass the time period from 1960 to 2105, following the Coupled Model Intercomparison Project 5 (CMIP5) protocol. Notwithstanding the accurate reproduction of large scale ocean-atmosphere coupled phenomena, like the ENSO phenomena over the Equatorial Pacific and the interhemispheric gradient mode over the Tropical Atlantic, the BESM-OA2.3 coupled model shows systematic errors on sea surface temperature and precipitation which resemble those of other global coupled climate models. Yet, the simulations demonstrate the models potential to contribute to the international efforts on global climate change research, sparking interest in global climate change research within the Brazilian climate modeling community, constituting a building block of the Brazilian Framework for Global Climate Change Research.

Diversos estudos com Modelos de Circulação Geral da Atmosfera (MCGAs) e Modelos Regionais (MR) considerando diferentes ecossistemas (CHARNEY et al., 1977; XUE ; SHUKLA 1993; CLARK et al., 2001; TAYLOR, 2002; OYAMA, 2002; XUE et al., 2004; SOUZA, 2006; OLIVEIRA, 2008; CUNHA, 2013) mostraram que a atmosfera é sensível às características físicas da vegetação e dos solos e que essas tem influência nas trocas de energia, água e momentum entre a superfície terrestre e a atmosfera. Outrossim, a representação inadequada ou insuficiente da superfície continental nos modelos meteorológicos pode ter um impacto negativo sobre a previsão do tempo e estudos climáticos (WILSON, 1985; HALL et al., 1995; SUD et al. 1996; DeFRIES et al., 1999; CHAMPEAUX et al., 2000; KANG et al., 2007). Com o desenvolvimento e consequente complexidade dos modelos globais e regionais, tornou-se necessário incluir uma representação mais realista da superfície nos esquemas de interação biosfera-atmosfera acoplados aos modelos atmosféricos, de forma a contemplar melhorias nas simulações dos processos envolvidos. Em modelagem meteorológica, vários modelos de superfície foram desenvolvidos para serem utilizados no modo desacoplado ou acoplados a modelos atmosféricos, tais como o modelo Simplified Simple Biosphere – SSiB (XUE et al. 1991), o Simple Biosphere Model-2 – SIB-2 (SELLER et al. 1995a,b), o Mosaic Land Surface Model – LSM (KOSTER; SUAREZ, 1996), o modelo Land Ecosystem Atmosphere Feedback – Leaf-3, (WALKO et al., 2000), o Community Land Model-2 – CLM2 (BONAN et al. 2002), o modelo Noah (EK et al. 2003), entre outros.

Brazil and Germany have set ambitious targets in order to effectively address the challenges associated with climate change and promote sustainable development using natural resources. In this context, both countries have intensified efforts to reduce the environmental impacts of energy consumption and promote the commercial exploitation of renewable energy resources like solar and wind energy in order to meet the growing energy demand due to the Brazilian social and economic development with a sustainable and clean approach. The NoPa program is a joint collaboration among CAPES and DAAD in order to support scientific partnership between Brazilian and German research institutions.

A variação da quantidade de nitrogênio reativo presente nos diferentes ambientes terrestres está intimamente ligada às mudanças ambientais, à contaminação de ecossistemas aquáticos e terrestres e à perda de biodiversidade. O entendimento sobre a acumulação de nitrogênio reativo no ambiente depara-se ainda com grandes lacunas e questões como quanto o aumento da deposição de nitrogênio reativo pode interferir no funcionamento de diferentes ecossistemas ou como ocorre a interação e o acoplamento do ciclo do nitrogênio com os outros ciclos tais como o do C, S e P ainda precisam de resposta. Desta forma a questão científica que se apresenta refere-se à quantificação da concentração e da deposição de espécies químicas de nitrogênio reativo nas formas, inorgânica e orgânica, presentes na atmosfera de algumas regiões do Estado de São Paulo. Esta pesquisa buscará determinar, a partir das medidas de concentração de diferentes espécies químicas, a deposição atmosférica das mesmas, em alguns locais com diferentes ambientes no estado de São Paulo viabilizando a utilização de um sistema de amostragem de baixo custo e com possibilidade de replicar o modelo estabelecido para outras regiões, estendendo-se assim a área de observação. Serão determinadas as concentrações em extrato aquoso das seguintes espécies químicas gasosas: $NH_{3}$, $HNO_{3}$, $SO_{2}$, HC1 e no aerossol $NH^{+}_{4}$, $NO^{-}_{3}$, $SO^{2-}_{4}$, $CI^{-}$, $Na^{+}$, $K^{+}$, $Ca^{2+}$, $Mg^{2+}$ presentes na atmosfera. Com os resultados desta pesquisa, espera-se que possamos contribuir com informações para avaliar a vulnerabilidade regional a eventuais mudanças na deposição de espécies reativas de nitrogênio, decorrentes de sua acumulação e deposição; identificar as possíveis mudanças nos padrões de deposição (caso ocorram) sobre os serviços dos ecossistemas bem como contribuir para o entendimento da conexão entre o componente atmosférico do ciclo do nitrogênio e os ciclos do C e do S, e como essas alterações podem interferir no clima.

Este relatório apresenta a metodologia de coleta de dados e a descrição inicial dos resultados obtidos no trabalho de campo com comunidades ribeirinhas do Rio Arapiuns, afluente do Rio Tapajós, realizado no período de 4 a 15 de junho de 2012, no município de Santarém, Pará. Esse trabalho amplia e reproduz a coleta de dados realizada para as comunidades ribeirinhas do Tapajós em 2009 para análises de redes e de infraestrutura. Nosso objetivo foi caracterizar os núcleos populacionais quanto à: infraestrutura, serviços de saúde e educação, uso da terra, uso de produtos extrativistas de origem animal e vegetal e percepção de bem estar, buscando identificar relações de organização e interdependência entre os núcleos. Foram percorridos aproximadamente 300 km com um barco motor, pelas duas margens do Rio Arapiuns e de seus afluentes, os rios Aruã e Maró. As informações foram coletadas em 49 comunidades ribeirinhas, entrevistando informantes chaves a partir de questionários semiestruturados. Os núcleos populacionais correspondem a aldeias indígenas, vilas e comunidades e estão inseridas na Resex Tapajós-Arapiuns, no Projeto de Assentamento Extrativista Lago Grande, na Terra Indígena do Maró e na Gleba Nova Olinda. De modo geral, a infraestrutura é precária: as localidades carecem de equipamentos e serviços urbanos, para os quais dependem de Santarém. Diferentemente da oferta de ensino fundamental, presente na maioria dos núcleos, há poucas escolas de ensino médio, o que exige o deslocamento da população. Mobilidade também é necessária para a população acessar postos de saúde, médicos e hospitais. O mosaico de terras públicas da região restringe a legalização fundiária e o uso da terra. Agricultura e pecuária são apenas para subsistência e praticadas em pequenas áreas de capoeira. As principais atividades econômicas geradoras de renda são a produção de farinha de mandioca, o artesanato e a pesca. A produção de farinha é reduzida quando há incremento de renda por outras atividades, como artesanato e turismo, ou por benefícios como aposentadoria e bolsa família. O artesanato depende do mercado e da possibilidade de comercialização, principalmente de utensílios para processar a mandioca. A disponibilidade de pescado, mais importante para subsistência do que para a geração de renda, é sazonal, e no inverno alguns núcleos recorrem a outras fontes de proteína. O uso dos produtos extrativistas de origem vegetal e animal (PEVA) nas comunidades é de grande importância para consumo, embora pouco explorado para geração de renda e praticado sem manejo. Os indicadores de bem estar variam de regular a satisfatório, com positiva percepção de segurança, moradia, participação nas decisões, atividades de lazer, festividades, solidariedade e divisão equitativa de tarefas entre homens e mulheres. As principais demandas elencadas foram: melhorias na saúde, educação e abastecimento de água, seguidas pelo acesso à energia elétrica, telefonia, internet e apoio institucional para atividades de geração de renda. A caracterização apresentada neste relatório é preliminar. Análises mais detalhadas sobre as comunidades e as redes de serviço, transporte e abastecimento deverão ser realizadas após a transcrição completa e sistematização dos dados para uma base digital. Os resultados desse trabalho deverão ser reunidos com outros dados de campo e análises contribuindo para o melhor entendimento das redes urbanas do sudoeste paraense, na área de abrangência do DFS da BR -163.