Validação do Albedo da superfície terrestre obtido a partir de imagens do sensor Modis em área de Caatinga
O albedo da superfície, definido como a razão entre a radiação solar refletida e a radiação solar incidente, é uma medida indireta da energia solar absorvida pela superfície. É um importante parâmetro que afeta o balanço de radiação terrestre e, portanto, é considerado em estudos do cl...
por Portal Padrão
publicado
26/08/2009
1:26 PM
Calibration of the “simplified simple biosphere model-SSiB” for the Brazilian Northeast Caatinga
Brazilian Northeast region is covered largely by vegetation adapted to the arid conditions and with varied physiognomy, called caatinga. It occupies an extension of about 800.000 km that corresponds to 70% of the region. In recent decades, considerable progress in understanding the micrometeorologic...
por Portal Padrão
publicado
26/08/2009
1:25 PM
Solar radiation assessed by CPTEC model GL: a comparison between results with GOES and MSG over Northeastern Brazil
Model GL version 1.2 runs operationally at CPTEC/INPE assessing daily solar radiation from GOES 10 VIS imagery. Besides basic hypotheses about atmospheric variables, the fundamental local variable is reflectance at a pixel observed by satellite (Ceballos et al. 2004). Daily irradiation is obtained b...
por Portal Padrão
publicado
26/08/2009
1:24 PM
Modelling of the decrease of tropical-forest resilience in Amazonia as affected by deforestation and fires
Biome models of the global climate-vegetation relationships indicate that most of the Brazilian Amazon has potential for being covered by tropical forests. From current land-use processes observed in the region, however, several areas of natural forests were lead to different states dominated by deg...
por Portal Padrão
publicado
26/08/2009
1:23 PM
Potential for advancing fire research in Amazonia by integrating ground-based, remote sensing and modeling studies for the region
Fire research is key for understanding the ecosystem functions of Amazonia and the sustainability of land-use practices in the region. Fires are significant disturbances to biogeochemical cycles, and have important links to land use and climate. Major methods for studying fires include fieldwork, re...
por Portal Padrão
publicado
26/08/2009
1:22 PM
An architecture for agent-based modelling and simulation of geospatial phenomena
This work presents a general architecture for building and simulating agent-based models that use real-world geospatial data, take into account all the ways geospatial data can feed these models. We focus on how data can be used to create an initial arrangement for the model, as if it was a static r...
por Portal Padrão
publicado
26/08/2009
1:21 PM
Large-scale changes in precipitation and temperature in South America under climate change – ensemble climate model projections and uncertainty assessments
Following the extensive conclusions from the IPCC (Intergovernmental Panel on Climate Change) Fourth Assessment Report and other reports (including INPEs report 2007 - ww.cptec.inpe.br/mudancas_climaticas) we have credible evidence that the climate is changing across the world. But it is important t...
por Portal Padrão
publicado
26/08/2009
1:20 PM
Analysis of errors in solar heating rate calculations with broadband radiation codes in cloud layers
The accuracy of broadband radiation codes for models is less studied for cloudy atmosphere than for cloud- free atmosphere. In this study, various test cases are proposed for atmosphere with clouds. The calculations of the heating rate (HR) profiles were made for 15 cloudy test cases with vertical r...
por Portal Padrão
publicado
26/08/2009
1:20 PM
Filtragem de momentum por escala pelo dossel da floresta amazônica
São utilizados dados de velocidade do vento obtidos por anemômetros dispostos verticalmente em uma torre de 60m na Rebio- Jarú, RO, projeto LBA. O objetivo foi de analisar as características da filtragem de momentum por escala pelo dossel da floresta amazônica. Aplicou-se a ondeleta de Morlet ...
por Portal Padrão
publicado
26/08/2009
1:19 PM
High-speed video observations of positive ground flashes produced by intracloud lightning
High-speed video recordings of two lightning flashes confirm that positive cloud-to-ground (CG) strokes can be produced by extensive horizontal intracloud (IC) discharges within and near the cloud base. These recordings constitute the first observations of CG leaders emanating from IC discharges of ...
por Portal Padrão
publicado
26/08/2009
1:18 PM
Archaeological mounds in Marajó Island in northern Brazil: a geological perspective integrating remote sensing and sedimentology
Earthen mounds with archaeological artifacts have been well known in Marajó Island since the 19th century. Their documented dimensions are impressive, e.g., up to 20 m high, and with areas as large as 90 ha. The mounds, locally known as tesos, impose a significant relief on the very low-lying lands...
por Portal Padrão
publicado
26/08/2009
1:17 PM
Patterns of water and heat flux across a biome gradient from tropical forest to savanna in Brazil
We investigated the seasonal patterns of water vapor and sensible heat flux along a tropical biome gradient from forest to savanna. We analyzed data from a network of flux towers in Brazil that were operated within the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA). These tower sites ...
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