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The droughts of 1997 and 2005 in Amazonia: floodplain hydrology and its potential ecological and human impacts

It is well known that most of the severe droughts in Amazonia, such as that of 1997, are El Nio-related. However, in 2005, the Amazon was affected by a severe drought that was not El Nio-related, as most of the rainfall anomalies that have happened in southwestern Amazonia are driven by sea surface ...
  • por Portal Padrão
  • publicado
  • 22/02/2013
  • 4:29 PM

Electric fields changes produced by positives cloud-to-ground lightning flashes

Positive flashes correspond to approximately only 10\% of the total number of flashes produced by a thunderstorm. However, strokes with high peak currents and long continuing currents are usually present in positive flashes. Therefore, positive flashes are responsible for more intense damage than th...
  • por Portal Padrão
  • publicado
  • 22/01/2013
  • 4:22 PM

The impacts of global climate changes on the wind power density in Brazil

Brazils wind energy production has escalated up recently. However, the long-term wind projects do not include the yet unknown impacts of climate changes on wind power. This work is an assessment of these impacts by applying forecasts of a climate model and trend analysis over climatological time ser...
  • por Portal Padrão
  • publicado
  • 22/01/2013
  • 2:33 PM

Solar radiation forecast using artificial neural networks.

The fast increase in importance of the solar energy resource as viable and promising source of renewable energy has boosted research in methods to evaluate the short-term forecasts of the solar energy resource. There is an increase on demand from the energy sector for accurate short-term forecasts o...
  • por Portal Padrão
  • publicado
  • 26/12/2012
  • 1:22 PM

Socio-climatic hotspots in Brazil.

Brazil suffers yearly from extreme weather and climate events, which can be exacerbated in a warmer climate. Although several studies have analyzed the projections of climate change in Brazil, little attention has been paid to defining the locations that can be most affected, and consequently have a...
  • por Portal Padrão
  • publicado
  • 26/11/2012
  • 1:36 PM

Estimating greenhouse gas emissions from cattle raising in Brazil.

The study estimated, for the first time, the greenhouse gas emissions associated with cattle raising in Brazil, focusing on the period from 2003 to 2008 and the three principal sources: 1) portion of deforestation resulting in pasture establishment and subsequent burning of felled vegetation; 2) pas...
  • por Portal Padrão
  • publicado
  • 23/11/2012
  • 2:19 PM

Time-intervals between negative lightning strokes and the creation of new ground terminations.

On average, negative cloud-to-ground (CG) lightning flashes produce 3 to 5 return strokes, and a new ground termination is produced when any stroke after the first strikes the ground in a different place. In order to understand better the physical factors that affect the formation of new ground term...
  • por Portal Padrão
  • publicado
  • 26/10/2012
  • 12:59 PM

Sazonalidade da precipitação sobre o Nordeste setentrional brasileiro nas simulações do IPCC-AR4.

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  • por Portal Padrão
  • publicado
  • 26/09/2012
  • 1:34 PM

Coupled ocean-atmosphere variations over the south atlantic ocean.

The role of ocean-atmosphere interactions on summer rainfall over the South Atlantic Ocean is explored through the use of coupled ocean-atmosphere models. The Brazilian Center for Weather Forecast and Climate Studies (CPTEC) coupled ocean-atmosphere general circulation model (CGCM) and its atmospher...
  • por Portal Padrão
  • publicado
  • 26/09/2012
  • 1:23 PM

Scenarios for solar thermal energy applications in Brazil.

The Solar and Wind Energy Resource Assessment (SWERA) database is used to prepare and discuss scenarios for solar thermal applications in Brazil. The paper discusses low temperature applications (small and large scale water heating) and solar power plants for electricity production (concentrated sol...
  • por Portal Padrão
  • publicado
  • 26/09/2012
  • 1:19 PM

Distributed hydrological modeling of a micro-Scale rainforest watershed in Amazonia: model evaluation and advances in calibration using the new HAND terrain model.

Three sections of the Asu catchment, which is located within the Cuieiras Reservation 80 km northwest of Manaus in Central Amazonia, Brazil, were gauged to create nested catchments of the first (0.95 km2), second (6.58 km2) and third (12.43 km2) Strahler orders. As the Cuieiras reserve contains pris...
  • por Portal Padrão
  • publicado
  • 23/09/2012
  • 2:59 PM

Climate fields over South America and variability of SACZ and PSA in HadGEM2-ES CMIP5.

Historical simulations (present climate) and projections under RCP8.5 scenario (future climate) by HadGEM2-ES of temperature and precipitation are analyzed during the four seasons in South America. Projections of precipitation are discussed in terms of atmospheric circulation. The South Atlantic Con...
  • por Portal Padrão
  • publicado
  • 23/09/2012
  • 2:25 PM