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O objetivo desse estudo foi analisar a relação entre descargas elétricas, associadas à precipitação dentro de áreas selecionadas no leste da Amazônia as áreas foram escolhidas por encontrarem-se aproximadamente na mesma latitude buscando observar a sazonalidade dos sistemas precipitantes causadores de raios e sua penetração no continente, observando as características climatológica distintas de cada área de estudo. Foram utilizados dados de raios coletados pela rede STARNET no período de setembro 2008 a setembro de 2010 e dados de chuva disponibilizados por vários sistemas de observação de superfície. Os resultados das análises desses dois anos mostraram que sistemas meteorológicos de grande escala acompanhados de sistemas de escala menores, parecem atuar primeiramente em Belém e vão adentrando o continente atingindo as outras áreas de estudo. Devido a notória incidência de raios na região amazônica que por sua vez tem causado perdas humanas, materiais e danos ao meio-ambiente estudo das descargas atmosféricas no leste da Amazônia e seus efeitos socioambientais têm obtido maior relevância a partir da divulgação de resultados de vários trabalhos. A B S T R A C T The objective of this study was to analyze the relationship between electric discharges associated with the precipitation in selected areas of the eastern Amazon region. The areas were chosen within approximately the same latitude, seeking to observe the seasonal influence of the precipitating systems on lightning production, and their penetration into the continent, considering the different climatologic characteristics of each study area. Data collected by the STARNET lightning detecting network from September 2008 to September 2010 were processed, as well as, rainfall data available from several observing systems at the surface. The results of the monthly data analysis indicated a better relationship between lightning and rainfall in the area of Belém and lower correlation for Caxiuanã and Santarem. This indicates that the Intertropical Convergence Zone controls these variables near the Ocean, while small scale systems and the South Atlantic Convergence Zone control them in the interior of the continent. It appears that the four surface types discriminated for each area, did not contribute significantly to change the relationship between the main variables, in this study. This work has shown also that, during the dryer season, the correlation between lightning occurrences and rainfall is higher in all three areas; however, during the rainy season, it was observed that the rainfall maxima occurred about two months after the lightning incidence maxima. Keywords:Amazon, lightning, precipitation, climatology

O objetivo desse estudo foi estimar a precipitação media quinzenal na bacia do Rio Tocantins a partir de dados observados simultaneamente de ocorrência de raios, incidentes em área a montante da represa da Hidroelétrica de Tucuruí. Em geral, a relação entre essas variáveis não é linear e pode variar com o clima regional. Como a Amazônia já é razoavelmente coberta por redes de monitoramento continuo das ocorrências de raios, esse estudo pode contribuir para corrigir deficiências na obtenção de dados de precipitação, por outros meios de observação, nessa Região. As estimativas poderão subsidiar modelos numéricos para previsão de secas, enchentes e nível de água nas represas. Foram utilizados dados de raios coletados pela rede STARNET no período de setembro 2008 a setembro de 2010 e dados de chuva disponibilizados por vários sistemas de observação de superfície. Os resultados das análises desses dois anos mostraram que as médias quinzenais de ocorrências de raios e chuvas têm um comportamento sazonal semelhante, influenciado pelas oscilações de sistemas de grande escala como a ZCIT e ZCAS, e outros sistemas em meso escala. Correlações entre as variáveis foram apresentadas. Análises da relação entre cota de rios e raios indicaram que para períodos curtos houve boa correlação entre essas variáveis. Portanto o método desenvolvido nesse trabalho pode ser estendido satisfatoriamente e a baixo custo para suprir deficiências das redes de observações pluviométricas ou hidrológicas em outras bacias hidrográficas e/ou áreas de características fisiográficas distintas e de grande interesse socioeconômico na Amazônia. A B S T R A C T The main objective of this study was to estimate the biweekly average precipitation within the Tocantins River basin, using simultaneous data from lightning occurrences over an area up river from the Tucurui hydroelectric power dam. In general, the relation between these variables is not linear and may vary according to the regional climate. Considering that the Amazon Region is now reasonably covered by continuous monitoring lightning detection networks, this study will contribute to correct precipitation data collection deficiencies, by other means, in this Region. These estimates may subsidize numerical models to forecast droughts, floods and the water level at the reservoirs. Lightning events data collected by the STARNET system between September 2008 and September 2010 were processed, as well as, rainfall data from the available surface observation systems. The results from the analysis for this two years period showed that, both the biweekly averages of the lightning occurrences and rainfall have similar seasonal behaviors, influenced by large scale systems oscillations such as the ITCZ and SACZ, and meso scale systems. The correlations between these variables were presented in the work. Analysis of the river levels versus lightning numbers over short periods showed a good correlation between these variables. Therefore, the developed methodology for this work can be extended satisfactorily and at low cost, to remedy deficiencies of pluviometric and hydrologic observation networks, in other hydrographic basins and/or areas of distinct physiographic characteristics and great socio economic interest in the Amazon Region. Keywords : Amazon Region. Lightning. Rainfall. Hydrographic Basins

A regiao norte do Brasil, que inclui uma parte da Amazonia, possui condicoes climaticas que favorecem a ocorrencia de chuvas ao longo de todo o ano, muitas delas com grande quantidade de descargas atmosfericas. Um conhecimento detalhado da variabilidade espacial e temporal desses eventos pode ajudar tanto no planejamento de sistemas de protecao de linhas de transmissao de energia eletrica, sistemas de telecomunicacoes, como no apoio as populacoes que habitam nessa regiao. Neste trabalho foi feita uma analise estatistica de dados da rede de deteccao de raios Starnet, num total de mais de 220 milhoes de eventos que ocorreram na area de estudo durante os anos de 2009 a 2015, extraindo-se deles informacoes relevantes quanto as ocorrencias de descargas atmosfericas na regiao. Como resultado das analises estatisticas, foram produzidos mapas com a densidade de raios, mapa de dias de tempestade e graficos mostrando a sua distribuicao horaria, mensal e por dia e hora ao longo do ano. Spatial and Temporal Variability of Lightning in the Northern Region A B S T R A C T The Northern region of Brazil, which includes part of the Amazon, has climatic conditions that favour the occurrence of rainfall throughout the year, many of them with a large number of lightning strikes. Detailed knowledge of the spatial and temporal variability of these events can help both in the planning of protection systems for electric power transmission lines, telecommunications systems as in supporting the populations that live in that region. In this research, a statistical analysis of the Starnet lightning location system data was produced, in a total of more than 220 million events that occurred in the study area during the years of 2009 to 2015, extracting from them relevant information regarding the occurrences of lightning strikes in the region. As a result of this statistical analysis, maps were produced with the lightning density and thunderstorm days over the region, with graphs showing their monthly, daily and hourly distribution throughout the year. Keywords: northern region, lightning density, keraunic map

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 SIPAM's LDN system, over two areas where operational sub systems of transmission lines are installed. Statistical relations were drawn between the monthly lightning occurrence density and the number of power outages of the electric systems for both areas studied. The results showed that, although with some delays between these variables peaks, the number of power disruptions has a tendency to follow the behavior of the lightning occurrence densities variations. The numerical correlations were positive and may be useful to the transmission lines maintenance crews at least for the Belém-Castanhal electricity distribution sub system. Evidence was found, that the SST's over certain areas of the Pacific and Atlantic Oceans, influence convection over the area of interest, and may help to prognosticate the periods of intense electric storms, requiring repair readiness for the regional electric systems. Os registros de desligamentos dos sistemas de distribuição de energia elétrica, na Amazônia oriental, apresentaram um grande número de eventos atribuídos à incidência de raios, durante o período de 2006 a 2008. Dados da concessionária regional de energia foram comparados com observações de raios feitas pelo sistema de detecção do SIPAM sobre áreas que abrangem dois subsistemas de linhas de transmissão. Relações estatísticas, entre a densidade mensal de ocorrência de raios e o número de desligamentos dos sistemas elétricos, foram deduzidas para ambos os subsistemas estudados. Os resultados mostraram que apesar de alguns atrasos entre os picos dessas variáveis e o número de desligamentos de energia apresentam uma tendência de acompanhar as variações das densidades de eventos de raios. As correlações numéricas foram positivas e podem ser úteis às equipes de manutenção, pelo menos para o subsistema de Belém-Castanhal. Evidência foi encontrada de que anomalias de TSM, sobre certas áreas dos oceanos Pacífico e Atlântico, influenciam a convecção sobre a área de interesse, e consequentemente, podem ajudar a prognosticar os períodos de intensas tempestades, que necessitam de prontidão para reparos dos sistemas elétricos regionais.

O objetivo desse estudo foi analisar a relacao entre descargas eletricas, associadas a precipitacao dentro de areas selecionadas no leste da Amazonia as areas foram escolhidas por encontrarem-se aproximadamente na mesma latitude buscando observar a sazonalidade dos sistemas precipitantes causadores de raios e sua penetracao no continente, observando as caracteristicas climatologica distintas de cada area de estudo. Foram utilizados dados de raios coletados pela rede STARNET no periodo de setembro 2008 a setembro de 2010 e dados de chuva disponibilizados por varios sistemas de observacao de superficie. Os resultados das analises desses dois anos mostraram que sistemas meteorologicos de grande escala acompanhados de sistemas de escala menores, parecem atuar primeiramente em Belem e vao adentrando o continente atingindo as outras areas de estudo. Devido a notoria incidencia de raios na regiao amazonica que por sua vez tem causado perdas humanas, materiais e danos ao meio-ambiente estudo das descargas atmosfericas no leste da Amazonia e seus efeitos socioambientais tem obtido maior relevância a partir da divulgacao de resultados de varios trabalhos. 800x600 Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabela normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri",sans-serif;} A B S T R A C T The objective of this study was to analyze the relationship between electric discharges associated with the precipitation in selected areas of the eastern Amazon region. The areas were chosen within approximately the same latitude, seeking to observe the seasonal influence of the precipitating systems on lightning production, and their penetration into the continent, considering the different climatologic characteristics of each study area. Data collected by the STARNET lightning detecting network from September 2008 to September 2010 were processed, as well as, rainfall data available from several observing systems at the surface. The results of the monthly data analysis indicated a better relationship between lightning and rainfall in the area of Belem and lower correlation for Caxiuana and Santarem. This indicates that the Intertropical Convergence Zone controls these variables near the Ocean, while small scale systems and the South Atlantic Convergence Zone control them in the interior of the continent. It appears that the four surface types discriminated for each area, did not contribute significantly to change the relationship between the main variables, in this study. This work has shown also that, during the dryer season, the correlation between lightning occurrences and rainfall is higher in all three areas; however, during the rainy season, it was observed that the rainfall maxima occurred about two months after the lightning incidence maxima. Keywords :Amazon, lightning, precipitation, climatology

The lightning detection performance of the very low frequency VLF long-range Sferics Tracking and Ranging Network STARNET was evaluated by comparison with a simultaneous data collection made by the Sistema de Protecao da Amazonia Lightning Detection Network SIPAM-LDN. The study period was 110 days between August 2008 and March 2009, corresponding to a stable period of the STARNET network when it was operating with five sensors to cover the eastern Amazon region. The selected area of study corresponded to a circle of 130 km diameter within a homogeneous zone of detection efficiency DE of the SIPAM network. A method of coinciding flash identification time window of 1 ms and spatial range of 50 km was used for these two networks. The coinciding cloud-to-ground CG flashes were discriminated by polarity and peak current values from the SIPAM-LDN measurements. The total number of coincident CG flashes represented about 9.7% of the CG SIPAM data set. Moreover, 94 % of the coinciding CG flashes had a time error

Cloud-to-ground (CG) lightning variables, space and time distributions near the equator, over Eastern Amazon, were analyzed in this work. Over seven million lightning flash events of this type, detected by a VAISALA lightning detection network were processed. This data set was collected by the Brazilian Amazon Protection System between 2006 and 2008. The results showed the sub-areas of higher occurrence densities, polarity types, current peak intensity intervals, as well as, the hourly distributions of CG lightning, for this region. A considerable percentage (7%) of discharges with stroke current peaks above 100 kA, was observed. An attempt was made to compare the statistical results of this work with observations made elsewhere in Brazil and other regions of the world. The differences found suggest that, some regional peculiarities of the CG lightning parameter values should be taken into consideration, for electric and telecommunication systems protection against atmospheric electric discharges, in the Amazon Region.

O objetivo desse estudo foi estimar a precipitacao media quinzenal na bacia do Rio Tocantins a partir de dados observados simultaneamente de ocorrencia de raios, incidentes em area a montante da represa da Hidroeletrica de Tucurui. Em geral, a relacao entre essas variaveis nao e linear e pode variar com o clima regional. Como a Amazonia ja e razoavelmente coberta por redes de monitoramento continuo das ocorrencias de raios, esse estudo pode contribuir para corrigir deficiencias na obtencao de dados de precipitacao, por outros meios de observacao, nessa Regiao. As estimativas poderao subsidiar modelos numericos para previsao de secas, enchentes e nivel de agua nas represas. Foram utilizados dados de raios coletados pela rede STARNET no periodo de setembro 2008 a setembro de 2010 e dados de chuva disponibilizados por varios sistemas de observacao de superficie. Os resultados das analises desses dois anos mostraram que as medias quinzenais de ocorrencias de raios e chuvas tem um comportamento sazonal semelhante, influenciado pelas oscilacoes de sistemas de grande escala como a ZCIT e ZCAS, e outros sistemas em meso escala. Correlacoes entre as variaveis foram apresentadas. Analises da relacao entre cota de rios e raios indicaram que para periodos curtos houve boa correlacao entre essas variaveis. Portanto o metodo desenvolvido nesse trabalho pode ser estendido satisfatoriamente e a baixo custo para suprir deficiencias das redes de observacoes pluviometricas ou hidrologicas em outras bacias hidrograficas e/ou areas de caracteristicas fisiograficas distintas e de grande interesse socioeconomico na Amazonia. Normal 0 false false false PT-BR X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabela normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:8.0pt; mso-para-margin-left:0in; line-height:107%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri",sans-serif; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-ansi-language:PT-BR;} A B S T R A C T The main objective of this study was to estimate the biweekly average precipitation within the Tocantins River basin, using simultaneous data from lightning occurrences over an area up river from the Tucurui hydroelectric power dam. In general, the relation between these variables is not linear and may vary according to the regional climate. Considering that t he Amazon Region is now reasonably covered by continuous monitoring lightning detection networks, this study will contribute to correct precipitation data collection deficiencies, by other means, in this Region. These estimates may subsidize numerical models to forecast droughts, floods and the water level at the reservoirs. Lightning events data collected by the STARNET system between September 2008 and September 2010 were processed, as well as, rainfall data from the available surface observation systems. The results from the analysis for this two years period showed that, both the biweekly averages of the lightning occurrences and rainfall have similar seasonal behaviors, influenced by large scale systems oscillations such as the ITCZ and SACZ, and meso scale systems. The correlations between these variables were presented in the work. Analysis of the river levels versus lightning numbers over short periods showed a good correlation between these variables. Therefore, the developed methodology for this work can be extended satisfactorily and at low cost, to remedy deficiencies of pluviometric and hydrologic observation networks, in other hydrographic basins and/or areas of distinct physiographic characteristics and great socio economic interest in the Amazon Region. Keywords : Amazon Region. Lightning. Rainfall. Hydrographic Basins

Eventos de raios nuvem-solo registrados pela rede de detecção do SIPAM, integrada por 12 sensores VAISALA LPATS IV, distribuídos no leste da Amazônia, foram analisados durante 4 tempestades com ocorrência de precipitação intensa em Belém-PA-Brasil, em 2006-2007. Esses casos selecionados, correspondem a eventos de chuva com mais de 25 mm/hora ou 40 mm/ 2 horas, de precipitação registrada por um pluviômetro instalado em 1º 47' 53" and 48º 30' 16" O. Com centro nessa localização, um círculos de 30, 10 e 5 km de raio foram traçados através de um sistema de informação geográfica e os dados de eventos de raios nessas áreas foram separados para analise. Durante essas tempestades, os eventos de raios ocorreram de maneira quase aleatória, sobre a área maior que já havia sido previamente coberta por sistemas convectivos de mesoescala, em todos os casos. Esse trabalho também mostrou a grande influencia dos sistemas de larga escala nas condições de tempo que levaram às tempestades severas estudadas. Adicionalmente, foi observado que, quando existe interação entre sistemas de larga e meso escalas, tanto a precipitação como o numero de relâmpagos aumentaram significativamente e a atividade elétrica nos círculos maiores pode anteceder a chuva no ponto central. CG Lightning flashes events monitored by a LDN of the Amazon Protection System, which included 12 LPATS IV VAISALA sensors distributed over eastern Amazonia, were analyzed during four severe rainstorm occurrences in Belem-PA-Brazil, in the 2006-2007 period. These selected case studies referred to rainfall events, which produced more than 25 mm/hour, or more than 40 mm/ 2 hours of precipitation rate totals, registered by a tipping bucket automatic high-resolution rain gauge, located at 1º 47' 53" S and 48º 30' 16" W. Centered at this location, a 30 ,10 and 5 km radius circles were drawn by means of a geographic information system, and the data from lightning occurrences within this larger area, were set apart for analysis. During these severe storms the CG lightning events, occurred almost randomly over the surrounding defined circle, previously covered by mesoscale convective systems, for all cases studied. This work also showed that the interaction between large-scale and mesoscale weather conditions have a major influence on the intensity of the storms studied cases. In addition to the enhancement of the lightning and precipitation rates, the electric activity within the larger circles can precede the rainfall at central point of the areas.

As variações da temperatura e do fluxo de calor em solos sob a floresta nativa de Caxiuanã e uma pastagem natural da Ilha do Marajó, foram monitoradas continuamente no período de dezembro de 2001 a fevereiro de 2005. O objetivo foi comparar as respostas térmicas ao aquecimento diário, dos solos desses dois tipos de ecossistemas existentes no leste da Amazônia, para subsidiar modelos regionais de clima e avaliação dos efeitos de desmatamento. Além das medidas de campo das variáveis acima citadas, em três níveis até a profundidade de 0,5 m, esse trabalho apresenta estimativas de fluxo de calor e propriedades dos solos, tais como: difusividade e condutividade térmicas, profundidade de amortecimento e velocidade de propagação do pulso de aquecimento diário, determinados por métodos analíticos. Os resultados mostraram o contraste sazonal e outras diferenças significativas de respostas entre os dois sítios estudados, destacando o papel do conteúdo de água nos perfis térmicos verticais em cada tipo de solo. O ajuste obtido entre as medidas e os valores calculados das variáveis, indica a possibilidade de generalização dos resultados para outros sítios de ecossistemas similares na Amazônia. Temperature and heat flux variations in soils, at sites of the Caxiuanã native forest and a natural pasture in Marajó Island, were continuously monitored in the period between December, 2001 and February, 2005. The objective was to compare the thermal responses to the daily heating, of the soils of these two types of ecosystems present in eastern Amazonia, in order to subsidize regional climate models and the evaluation of deforestation effects. Besides the field measurements of the above mentioned variables, at three levels down to 0.50 m depth, this work presents estimates of the heat flux and soil properties such as: thermal diffusivity and conductivity, damping depth and propagation speed of the daily heating pulse, determined by analytical methods. The results showed the seasonal contrast and other significant differences between the responses of the two studied sites, especially regarding the role of the water contents on the vertical temperature profiles of each soil type. The observed fitting between the measurements and the computed values of the variables, indicates the possibility of generalization of the results to other similar ecosystems sites in Amazonia.

Weather patterns recognition is very important to improve forecasting skills regarding severe storm conditions over a given area of the Earth. Severe weather can damage electric and telecommunication systems, besides generating material losses and even losses of life (Cooray et al., 2007; Lo Piparo, 2010; Santos et al., 2011). In especial for the electrical sector, is strategic to recognize weather patterns that may help predict weather caused damages. Severe weather forecast is crucial to reduce permanent damage to the systems equipments and outages in transmission or distribution lines.

Cloud-to-ground (CG) lightning variables, space and time distributions near the equator, over Eastern Amazon, were analyzed in this work. Over seven million lightning flash events of this type, detected by a VAISALA sensor network operated by the Brazilian Amazon Protection System (SIPAM) between 2006 and 2008 were processed. The results show the sub-areas of higher frequency of occurrences, as well as the monthly and hourly distributions of CG lightning polarity type, current peak intervals for this region. The regional values of the CG lightning parameters should be taken into consideration on electric and telecommunication systems protection projects, against atmospheric electric discharges in the Amazon Region.

Atmospheric radiation components (incident and reflected solar radiation, incoming and outgoing long wave radiation) and net radiation flux, were measured by sensors installed at 52 m height above ground, over Caxiuana’s forest, in eastern Amazonia. A data logger sampled these variables at 30 minutes intervals producing two sets of data. The first corresponding to a three month (March to May) period of the local rainy season and the second collected during the dry season (August to October) of 2005. This experiment allowed to determine the whole radiation average balance over this native forest site, and to point out the differences of hourly behaviors of the variables for different seasons. Comparisons between the results of this study and others performed at other forest and pasture sites in the Amazon were made. An evaluation of the performance of empiric equations derived by other authors, to estimate the long wave atmospheric radiation, was made, considering the measured values of this variable, during selected cloudy and clear sky days.

Air temperatures at 8, 30 and 52 m above ground and vertical fluxes of latent heat and sensible heat at 54 m height, were measured during one month of the dry season (August, 2005) and another month (April, 2005) of the rainy season at Caxiuana’s forest micrometeorological tower. The average temperature profiles for daylight and night periods, as well as, the sensible and latent heat fluxes estimated and measured, showed significantly different and frequently opposite behavior of these quantities, within two layers defined between 8 and 30 m, below the forest canopy, and 30 to 52 m, above the canopy. The canopy seems to act as a heat source during the daylight hours and a sink of heat at night. Overall, the sum of the sensible and latent heat fluxes may reach 90% of the short wave net radiation, over this site. The results suggest that more attention should be given to the air layer below the canopy, if one seeks to understand the heat and water vapor exchanges between the soils surface and the atmosphere, above the canopy of such type of forest.