High-speed video and electromagnetic analysis of two natural bipolar cloud-to-ground lightning flashes
High-speed video records of two bipolar cloud-to-ground flashes were analyzed in detail. They both began with a single positive return stroke that was followed by more than one subsequent weak negative stroke. Due to the elevated cloud base height of its parent thunderstorm, the preparatory processe...
por Portal Padrão
publicado
21/08/2014
12:59 PM
Electric systems failures produced by CG lightning in eastern Amazonia.
Operational records of power outages of the electric energy distribution systems in eastern Amazonia presented a large number of events attributed to lightning strikes, during the 2006 to 2009 period. The regional electricity concessionary data were compared to actual lightning observations made by ...
por Portal Padrão
publicado
20/08/2014
4:26 PM
Classificação de eventos extremos de precipitação em múltiplas escalas de tempo em Belém-PA: utilizando o índice de precipitação normalizada.
O Índice de Precipitação Normalizada (SPI) é utilizado para quantificar o déficit e/ou excesso de precipitação nas múltiplas escalas de tempo. Ele tem se mostrado bastante útil no monitoramento da precipitação, principalmente pela sua flexibilidade, simplicidade de cálculo e interpretaç...
por Portal Padrão
publicado
20/08/2014
4:21 PM
Variabilidade da precipitação no Estado do Pará por meio de análise em componentes principais
O método da Análise Fatorial em Componentes Principais e dos Agrupamentos Hierárquicos foram utilizados para determinar os padrões principais de variabilidade temporal e espacial, assim como identificação dos grupos homogêneos, da precipitação no Estado do Pará. Para isso utilizaram-se dad...
por Portal Padrão
publicado
20/08/2014
4:19 PM
Knowledge extraction from large climatological data sets using a genome-wide analysis approach: application to the 2005 and 2010 Amazon droughts.
Today, the volume of data generated in almost all disciplines, particularly in meteorology and climate science, is dramatically increasing. Among the challenges generated by this data deluge is the development of efficient knowledge discovery strategies. Here, we show that statistical and computatio...
por Portal Padrão
publicado
20/08/2014
4:16 PM
Impacts of landscape fragmentation on simulated precipitation fields in the Amazonian sub-basin of Ji-Paraná using the Eta model.
Numerical studies on impacts of landscape fragmentation due to land use and land cover change (LUCC) on precipitation fields over the Ji-Paraná basin in the Amazon region are carried out using atmospheric Eta model. Experiments consider historical data about LUCC over the basin from 1978 to 2000 an...
por Portal Padrão
publicado
20/08/2014
4:14 PM
Reliability evaluation of wind regime estimates provided by the brams model for alagoas state (Brazilian northeastern region): influence of nesting and horizontal resolution grids.
Observational data obtained at two wind towers located at the Alagoas State (Northeast of Brazil - NEB) were used to evaluate the influence of horizontal grid setup on the reliability of wind estimates provided by the numerical weather prediction model BRAMS. Statistical analysis were performed to e...
por Portal Padrão
publicado
20/08/2014
4:09 PM
Thunderstorm climatology of Brazil: ENSO and Tropical Atlantic connections.
In this report monthly thunderstorm days (TD) in 14 large cities of Brazil from 1951 to 2010 are compared with data obtained in the first part of the 20th century in the same cities and correlated with sea surface temperature (SST) of the equatorial Pacific Ocean and Tropical Atlantic Ocean. On aver...
por Portal Padrão
publicado
20/08/2014
4:07 PM
The surface radiation budget over South America in a set of regional climate models from the CLARIS-LPB project.
The performance of seven regional climate models in simulating the radiation and heat fluxes at the surface over South America (SA) is evaluated. Sources of uncertainty and errors are identified. All simulations have been performed in the context of the CLARIS-LPB Project for the period 1990-2008 an...
por Portal Padrão
publicado
20/08/2014
4:02 PM
River inflow and retention time affecting spatial heterogeneity of chlorophyll and water-air CO2 fluxes in a tropical hydropower reservoir.
Much research has been devoted to understanding the complexity of biogeochemical and physical processes responsible for the greenhouse gas (GHG) emissions from hydropower reservoirs. Spatial complexity and heterogeneity of GHG emission may be observed in these systems because it is dependent on floo...
por Portal Padrão
publicado
20/08/2014
4:00 PM
Uncertainties in greenhouse gases inventories – expanding our perspective.
Strategies for mitigating global climate change require accurate estimates of the emissions of greenhouse gases (GHGs). A strong consensus in the global scientific community states that efforts to control climate change require stabilization of the atmospheric concentration of GHGs (as per a recent ...
por Portal Padrão
publicado
20/08/2014
3:57 PM
Rainfall and climate variability: long-term trends in the metropolitan area of São Paulo in the 20th century.
We investigated spatial-temporal variability and long-term trends of rainfall over the Metropolitan Area of São Paulo (MASP). Due to a lack of continuous and consistent rainfall observations in the MASP, a database for the spatial analysis was created from a composite of 94 stations, with daily rai...
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