21 research outputs found
Efeitos de elementos climáticos na deposição e decomposição da serapilheira de Mata Atlântica no Estado de Alagoas
The Mata Atlântica forest is one of the most worldwide deforested ecosystems. This ecosystem survives in small fragments that still plays an important role in the litter decomposition. The main aim of this paper was to verify the influence of climate elements in the seasonal deposition of litter and its decomposition in a fragment of Mata Atlântica. The study was carried out throughout October/2009 to March/2019. The data of Downward Radiation and Rainfall were stored every 10 minutes and collected in a Forest Reserve in Coruripe, Alagoas State. The normal litter had been monthly collected by nylon mesh meanwhile the accumulated litter was collected each 3 moths by metal collectors. All the collected materials were drought, weighted and quantified in Mg ha-1. It was estimated the decomposition rate, the average time of the accumulated litter renew and the necessary time (year) to the extinction of 50% (T0,5) and 95% (T0,05) of litter. The annual average of rainfall was 1233,92 mm. The average of downward solar radiation was 437,92 W m-2. The litter production was seasonal with lowest accumulation during the wet season and highest in the dry season. The decomposition coefficient average was 0,71 and the average time necessary to the extinction of 50 and 95% of the litter was, respectively, 1 and 4,2 years. Thus, stood out the seasonality of the production and accumulation of the total litter and its association with the rainfall regime.A Mata Atlântica é um dos ecossistemas mais devastados do mundo. Este ecossistema sobrevive em pequenos fragmentos que possuem um papel importante na deposição de serapilheira. O objetivo desse trabalho foi verificar a influência de elementos climáticos na sazonalidade da deposição de serapilheira acumulada e, sua decomposição, em um fragmento de Mata Atlântica. O estudo foi realizado no período de outubro/2009 a março/2019. Os dados de Radiação Solar Global e Precipitação foram armazenados a cada 10 minutos e coletados em uma Reserva Florestal, em Coruripe, Alagoas. A serapilheira normal foi coletada mensalmente por malhas de náilon enquanto que a serapilheira acumulada foi coletadas a cada 3 meses por coletores de metal. Os materiais coletados foram secos, pesados e quantificados em Mg ha-1. Foi estimada a taxa de decomposição, o tempo médio de renovação de serapilheira acumulada e o tempo necessário (anos) para o desaparecimento de 50% (T0,5) e 95% (T0,05). A precipitação média anual acumulada foi de 1233,92 mm. A Radiação Solar Global apresentou média de 437,92 W m-2. A produção de serapilheira apresentou sazonalidade com os menores acúmulos na estação chuvosa e maiores na seca. O coeficiente de decomposição médio foi de 0,71 e o tempo médio necessário para o desaparecimento de 50 e 95% da serapilheira foi de aproximadamente 1 e 4,2 anos, respectivamente. Por fim, evidenciou-se sazonalidade na produção total e no acumulo de serapilheira e a associação com o regime pluviométrico
DOWNWARD LONGWAVE RADIATION ESTIMATES FOR CLEAR AND ALL-SKY CONDITIONS IN CENTRAL AMAZONIA
The downward longwave radiation (L↓), really is difficult of the net radiation the measured values component. Therefore, different parameterizations have been proposed to estimate it. Thus, in this study we evaluated the performance of various parameterizations for the L↓ flows estimated and their interaction with other variables measured as well as the air temperature and water vapour pressure interactions with L↓. In this study evaluates the performance of the downward longwave radiation parameters for clear and cloudy sky days applied in Central Amazonia region. The datasets used in this study was measured from micrometeorological tower controlled by Large Scale Biosphere Atmosphere experiment in Amazonia (LBA) from Manaus city, Amazonas. It was also found that precipitation and water vapour pressure exert enough on L↓ flows influence, especially in the wet season. The models for clear-sky conditions proposed, using their original coefficients trend to underestimate the L↓ flows measured. Best results for clear-sky were obtained with Idso & Jackson (1969), Brutsaert (1975) and Prata (1996)
Radiação fotossinteticamente ativa incidente e Refletida acima e abaixo do dossel de floresta de Mata Atlântica em Coruripe, Alagoas
The study of solar radiation is important to understand the several physical, chemical and biological processes that occur in the biosphere, particularly in the forest. The objective of this study has been to evaluate the temporal evolution of incident and reflected Photosynthetic Active Radiation (PAR) above and below the canopy of the Mata Atlantica forest. The study has been conducted in a Private Reserve Natural Heritage, located in the Coruripe city, Alagoas, during the period from October 2009 to September 2010, based on the PAR (2, 13, 26 m) observations obtained at the micrometeorological station, installed on a 24 meters high tower (10° 17' 36"S, 36° 17' 24"W, 160 m asl). According to the results the incident and reflected PAR outside (PAR↓_Ext and PAR↑_Ext) and inside (PAR↑_Spf) forest follow the seasonality imposed by the apparent motion of the Sun. The higher PAR values occur during the dry season, exceeding 600 and 12 W m-2, and during the wet season these averages was less than 300 and 8.0 W m-2, influenced by cloudiness. At the beginning and ending of sunlight time PAR↑_Spf values near zero were measured. The opposite measurements of about 14 W m-2, around 12 h (November and December) were observed
Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences
The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported
by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on
18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based
researchers who signed it in the short time span from 20 September to 6 October 2016
Downward longwave radiation estimate in Amazonia: a spectral analysis.
A radiação de onda longa incidente (L↓) é seguramente a componente do balanço de
radiação mais difícil de ser medida. Portanto, diferentes formulações têm sido propostas para estimá-la. Desta maneira, avaliou-se neste estudo o desempenho de várias formulações para a estimativa dos fluxos de L↓ e sua a interação com outras variáveis medidas, bem como as interações da temperatura do ar e da pressão de vapor d’água junto à L↓. Neste estudo foi utilizada a análise pela transformada em ondeletas (TO) como ferramenta matemática para a análise de variações locais de energia dentro das séries temporais aqui estudadas, pela sua
decomposição no tempo-frequência-espaço. Para investigar a correlação entre duas séries (L↓ com a temperatura do ar e da L↓ medida com as estimadas por cada modelo), empregou-se transformada cruzada em ondeletas e a coerência e fase em ondeletas. Os dados deste estudo compreendem o período de 01 de janeiro a 31 de dezembro de 2009, e são provenientes da torre micrometeorológica (K34) pertencente ao Experimento de Grande Escala da Biosfera Atmosfera na Amazônia (LBA) em Manaus, Amazonas. A TO revelou que no período de 36 horas, para todo período analisado, um persistente, homogêneo e forte espectro energético entre a L↓ e a
temperatura do ar, onde se constatou uma sinergia entre essas variáveis. Constatou -se ainda que a precipitação e a pressão de vapor d’água exercem bastante influencia nos fluxos de L↓, principalmente na estação chuvosa. A análise através da transformada cruzada e de coerência e fase em ondeletas no período de 32 a 64 horas. Já nos modelos ajustados foram no período de 16 a 64 horas. Os modelos propostos para condições de céu claro, com o uso de seus coeficientes originais, mostraram tendência em subestimar os fluxos de L↓ medidos. Com os ajustes nos
coeficientes, os modelos expuseram uma melhora nas estimativas nos fluxos de L↓.Para os modelos propostos para condições de céu nublado, estes exibiram um desempenho regular.The downward longwave radiation (L↓) component really is difficult of the net
radiation the measured. Therefore, different parameterizations have been proposed to estimate it. Thus, in this study we evaluated the performance of various parameterizations for the L↓ flows estimated and their interaction with other variables measured as well as the air temperature and water vapour pressure interactions with L↓. In this study we used by wavelet transform (WT) analysis as mathematical tool for energy of local variations analysis in the studied time series here by their frequency time-space decomposition. To investigate the correlation between two series (L↓ with air temperature and between L↓ measured with estimated), we used crosswavelet transform and coherency wavelets and phase angle. The datasets used in this study are of the January 01 to December 31 of 2009, measured from micrometeorological tower (named K34) controlled by Large Scale Biosphere Atmosphere experiment in Amazonia (LBA) from Manaus city, Amazonas. The WT showed that in 36 hours period, for the entire period analyzed, a persistent, smooth and strong energy spectrum between L↓ and the air temperature, which demonstrated a synergy between these variables. It was also found that precipitation and water vapour pressure exert enough on L↓ flows influence, especially in the wet season. The crosswavelet transform and coherency wavelets and phase angle analysis at 32 to 64 hours period.
Already in adjusted models were in the 16-64 hours period. With the adjustable coefficients, according to the environmental study area conditions, the models presents an improvement in the L↓ flows estimates. The cloudy skies models proposed, they exhibited a regular performance.Cape
Condensação a superfície na Amazônia em área de pastagem durante o experimento LBA/SMOCC: estudo de casos Surface condensation in the Amazon from the pasture area during LBA/SMOCC experiment: case studies
A condensação é uma variável indispensável para o entendimento de muitos processos hidrológicos e biológicos, os quais estão envolvidos em uma grande variedade de processos naturais que atuam em diferentes escalas espaciais e temporais. Na Amazônia é comum se observar tal fenômeno durante a madrugada, principalmente na época seca. Dentro da estrutura do experimento Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA), a campanha Smoke, Aerosols, Clouds, Rainfall, and Climate (SMOCC) foi realizada no período de setembro a novembro de 2002 no antigo sítio experimental do projeto ABRACOS, Rondônia, onde foi possível fazer detalhadas medições das propriedades químicas e físicas da atmosfera, dentre outros, a formação e dissipação da condensação do vapor d'água à superfície. De acordo com resultados obtidos, a formação da condensação ocorreu durante o período noturno por apresentar condições propícias para seu acontecimento. Para os eventos analisados nesse trabalho, foi observado que sua formação e manutenção ocorrem em função da intensidade do vento. Contudo, é possível argumentar que a calmaria é fator determinante para o surgimento da condensação.The condensation is an indispensable variable to the knowledge of some hydrologic and biologic process which is involved in a great natural process variety, which acts in different space and secular scales. In the Amazon is common to see such phenomenon on the dawn period, mainly in dry times. Inside the structure of Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA), the Smoke, Aerosols, Clouds, Rainfall and Climate (SMOCC) campaign was realized in a period between September and November 2002, on the old ABRACOS's small experimental farm, located in Rondônia, where was possible to make detailed measurements from of the chemical and physical properties of the atmosphere, the formation and waste of water vapor's surface. According to the results, the condensation formation occurred during nocturnal period for presenting propitious conditions for its event. To the events analyzed in this work, it was observed that its formation and maintenance had been in function of the wind intensity. However, it is possible to argue that the calmness is a determinative factor for the condensation sprouting
Análise das componentes do balanço de energia à superfície para a cidade de Manaus-AM a partir de imagens do sensor Landsat 5-TM
This research aimed to estimate and analyze the conduct of the surface radiation balance (Rn) in the city of Manaus-AM from information provided by Landsat 5-TM. The use of remote sensing in this context aims to fill a gap in Brazil, where the available data of solar radiation is very limited and mostly refers to climatological averages. For this, we used the procedures of the method Algorithm for Land Surface Balance - SEBAL. Was obtained values of the components of Rn-based reflective radiance from the channels (1, 2, 3, 4, 5, and 7) and the thermal channel (6) 5-Landsat TM. For comparative purposes, the main types of land cover were analyzed in the study area: urban area, water bodies, vegetation and bare soil. The emissivity values did not differ significantly between the targets, the values of albedo and surface temperature were directly proportional to the targets while for values Rn and long-wave emission was observed an inverse relationship in which the surfaces with higher emissivity values showed lower Rn. So clear was the contrast between the natural surfaces (vegetation and water bodies) that showed the highest values of Rn, while the urban area and areas of exposed soil showed lower values due to low capacity and high thermal conductivity heat material associated therewith.Pages: 7974-798
Concentração de dióxido de carbono em ambiente de savana na amazônia: estudo de caso
To investigate the correlation between two time series (CO2 versus air temperature and wind speed), we used coherency wavelets and phase angle. The datasets used in this study are in the October 16 of 2018, measured from micrometeorological tower in savanna natural area (2°49’30”S; 54°54’35”W; 82 m a.m.s.l.), Santarém (PA). The correlation between with CO2 concentration and air temperature detected high coherence (upper 0.8). When confronted with the wind speed, in microscale, detection a chaotic and disordered region, displaying very intermittent and showed “islands” (statistically significant), justified by the low amplitude between them. Naturally, the use of coherence wavelet and phase is fundamental to emphasize the between with CO2 and meteorological variables ration. It is evident, even for one day only, anti-phase relation between with the CO2 and air temperature signals. The temporal domain less than 32 minutes (microscale), the wind speed, at some moments, exerts a strong influence on the concentration of the referred gas (> 0.8), mainly from 09 to 15 local time.Para investigar a correlação entre duas séries temporais (CO2 com a temperatura do ar e com a velocidade do vento), empregou-se transformada de coerência e fase em ondeletas. Os dados deste estudo compreendem o período de 16 de outubro de 2018, e são provenientes da torre micrometeorológica instalada área natural de savana (2°49’30”S; 54°54’35”W; 82 m de alt.), em Santarém (PA). A correlação entre a concentração de CO2 comtemperatura do ar percebeu-se núcleos estatisticamente significativos (superior a 0,8). Ao confrontar com a velocidade do vento, em microescala, detectou-se uma região caótica e desordenada, apresentando “ilhas” (estatisticamente significativa) bastante intermitentes e setas atuando de forma aleatória, justificado pela baixa amplitude dessas séries. Seguramente, o emprego da coerência e de fase em ondeletas é fundamental para enfatizar as relações entre o CO2 com variáveis meteorológicas. Fica evidente, mesmo para o período de apenas um dia, anticorrelação entre os sinais de CO2 com a temperatura do ar. E que no domínio temporal inferior a 32 minutos (microescala), a velocidade do vento, em alguns momentos, exerce forte influência na concentração do referido gás (>0,8), principalmente das 09 às 15 HL