Publicações

We evaluated how land use change affected the nitrogen cycle and greenhouse gas fluxes. We measured soil temperature and water-filled pore space (WFPS), as well as nitrate and ammonium concentrations, mineralization and nitrification rates, and flux of CH4, CO2 and N2O in soils of pasture catchment and in soils of a forest catchment located on the north coast of the State of São Paulo. The main vegetation type in the forest catchment is primary Atlantic Montane Forest, while the pasture is an unfertilized 40-year old area planted with Brachiaria humidicola. Four plots were used for monthly sampling in each land use for an entire year. Soil temperature was always higher in pasture than in forest soils, while WFPS was lower in the pasture in relation to forest soils. Pasture soils were a weak source of CH4 during the winter months and a less strong sink of methane than the forest soils during the rainy summer months of the year. The annual median CH4 uptake was -1.8±1.0mgm-2d-1 in the forest in contrast to -0.6±0.9mgm-2d-1 in pasture soils. CO2 emissions were similar in the winter, but higher in the summer months in pasture soils in relation to forest soils. The annual median flux in the forest was 4.2±1.5μmolm-2s-1 and increased in the pasture to 6.5±2.9μmolm-2s-1. In contrast, N2O fluxes were smaller in the pasture (0.3±0.7ngcm-2h-1) than in forest soils (0.5±0.5ngcm-2h-1).

El Informe Especial sobre la Gestión de Riesgos de Eventos Extremos y Desastres en América Latina y el Caribe (SREX) fue encargado por el Panel Intergubernamental sobre el Cambio Climático (IPCC) en respuesta a la necesidad de proporcionar una asesoría específica sobre el cambio climático y los eventos meteorológicos y climáticos extremos (‘extremos climáticos’). El informe fue elaborado durante los últimos dos años y medio (2009-2011) con la participación de 220 autores expertos/as, 19 editores revisores/as y tomando en cuenta casi 19.000 comentarios. Es producto de tres rigurosos procesos de redacción, con revisión por parte de expertos/as y funcionarios/as gubernamentales. Los resultados, conclusiones y recomendaciones fueron aprobados por 194 gobiernos después de una reunión de cuatro días, en la que se aprobó el Resumen para Formuladores/as de Políticas.

O Relatório Especial sobre Gerenciamento de Riscos de Eventos Extremos e Desastres para Promover Adaptação à Mudança do Clima (SREX) foram comissionados pelo Painel Intergovernamental sobre Mudança do Clima (IPCC) em resposta a uma reconhecida necessidade de fornecer conselhos específicos sobre mudança do clima, condições meteorológicas extremas e eventos climáticos (‘extremos climáticos’). O relatório SREX levou mais de dois anos e meio para ser escrito, foi compilado por 220 autores especialistas, 19 editores revisores, e levou em conta mais de 19.000 comentários.

This paper reviews recent progress made in our understanding of the functioning and variability of the South American Monsoon System (SAMS) on time scales varying from synoptic to long-term variability and climate change. The SAMS contains one of the most prominent summertime climate patterns in South America, featuring a strong seasonal variability in a region lying between the Amazon and the La Plata Basin. Much of the recent progress is derived from complementary international programs, such as the Monsoon Experiment South America (MESA), as well as from ongoing international programs such as the Large Scale Biosphere Atmosphere Experiment in the Amazon Basin (LBA) and the La Plata Basin (LPB) Regional Hydroclimate Project, which includes the CLARIS LPB Europe-South America Network for Climate Change Assessment and Impact Studies in La Plata Basin Project. The latter assesses atmosphere-land surface interactions, the role of land use changes and aerosols from biomass burning considered as sources of variability and change in the SAMS functioning, characteristics and behaviour. The SAMS region is particularly susceptible to variations of climate due to the importance of hydroelectricity generation and the agricultural base of local economies. Also addressed in this report are projections of climate change and extremes, which are important for impact and vulnerability assessments. This discussion includes the need to identify and understand important processes that control the monsoonal climate, how these processes may vary and change, and how they may interact with key societal sectors, including water resource management, hydroelectric generation, agriculture, and agribusiness. This paper reports on the major contributions of MESA to the knowledge of characteristics, functioning and variability of the SAMS, and is based on recent studies and publications, and can be considered as an update of a previous review by C. S. Vera et al. (2006a).

This is an observational study of the large-scale moisture transport over South America, with some analyses on its relation to subtropical rainfall. The concept of aerial rivers is proposed as a framework: it is an analogy between the main pathways of moisture flow in the atmosphere and surface rivers. Opposite to surface rivers, aerial rivers gain (lose) water through evaporation (precipitation). The magnitude of the vertically integrated moisture transport is discharge, and precipitable water is like the mass of the liquid columnmultiplied by an equivalent speed it gives discharge. Trade wind flow into Amazonia, and the north/northwesterly flow to the subtropics, east of the Andes, are aerial rivers. Aerial lakes are the sections of a moisture pathway where the flow slows down and broadens, because of diffluence, and becomes deeper, with higher precipitable water. This is the case over Amazonia, downstream of the trade wind confluence. In the dry season, moisture from the aerial lake is transported northeastward, but weaker flow over southern Amazonia heads southward toward the subtropics. Southern Amazonia appears as a source of moisture to this flow. Aerial river discharge to the subtropics is comparable to that of the Amazon River. The variations of the amount of moisture coming from Amazonia have an important effect over the variability of discharge. Correlations between the flow from Amazonia and subtropical rainfall are not strong. However, some months within the set of dry seasons observed showed a strong increase (decrease) occurring together with an important increase (decrease) in subtropical rainfall.

Este Relatório de Atividades 2011-2012 que temos o prazer de apresentar, culmina com a etapa de estruturação da Rede CLIMA. O documento apresenta os destaques científicos de julho de 2011 a agosto de 2012, além de registrar o esforço conjunto em formação e qualificação de pessoal.

Uma grande questão que se coloca para as metrópoles brasileiras é se estão preparadas para enfrentar os impactos das mudanças climáticas. Durante os anos de 2008 a 2011, buscou-se lançar alguma luz sobre esse assunto por meio de um estudo interdisciplinar para identificar as vulnerabilidades das duas principais megacidades brasileiras—as regiões metropolitanas de São Paulo e do Rio de Janeiro. Este relatório trata da Região Metropolitana de São Paulo (RMSP), identificando impactos das mudanças climáticas na incidência de desastres naturais e na saúde, tendo como cenário de fundo a continuada expansão urbana nessa ampla região.