Artigo

Energy and water dynamics of a central Amazonian rain forest

This paper presents measurements of the energy and water budgets of a tropical rain forest near Manaus, Brazil, in central Amazonia, collected between September 1995 and August 1996. Fluxes of sensible and latent heat were measured using a three-dimensional eddy covariance system mounted above the f...

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Autor principal: Malhi, Yadvinder Singh
Outros Autores: Pegoraro, Emiliano, Nobre, Antônio Donato, Pereira, Maria G.P., Grace, John, Culf, Alistair D., Clement, Robert J.
Grau: Artigo
Idioma: English
Publicado em: Journal of Geophysical Research Atmospheres 2020
Assuntos:
Acesso em linha: https://repositorio.inpa.gov.br/handle/1/19085
id oai:repositorio:1-19085
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spelling oai:repositorio:1-19085 Energy and water dynamics of a central Amazonian rain forest Malhi, Yadvinder Singh Pegoraro, Emiliano Nobre, Antônio Donato Pereira, Maria G.P. Grace, John Culf, Alistair D. Clement, Robert J. Carbon Dioxide Correlation Methods Evapotranspiration Forestry Moisture Soils Tropics Turbulence Forest Canopy Hydraulic Property Seasonal Variation Solar Radiation Turbulent Mixing Water Budget Amazonas Amazonia Brasil Manaus South America This paper presents measurements of the energy and water budgets of a tropical rain forest near Manaus, Brazil, in central Amazonia, collected between September 1995 and August 1996. Fluxes of sensible and latent heat were measured using a three-dimensional eddy covariance system mounted above the forest canopy. Using a new approach to analysis of eddy covariance data, we found that the measured fluxes increased significantly when turbulent transport on timescales of 1 to 4 hours was taken into account. With this new analysis, the measured turbulent fluxes almost balanced the incoming net radiation, giving increased confidence in the accuracy of the measured fluxes. Of the 5.56 GJ m-2 yr-1 of solar radiation supplied over the year, 11% were reflected, 15% were lost as net thermal emission, 27% were transported through sensible heat convection, 46% used in evapotranspiration, and 0.5% were used; in net carbon fixation. Total annual evapotranspiration was calculated to be 1123 mm; accounting for 54% of total precipitation. Seasohality was an important influence: limited water availability during the dry season caused evapotranspiration to reduce by 50%. Total canopy conductance was linearly correlated to soil moisture content, with typical midday values ranging between 0.8 mol m-2 s-1 in the wet season and 0.3 mol m-2 s-1 in the dry season. Such seasonal behavior is likely to be prevalent in most tropical forest regions, and correct description of dry-season evapotranspiration will require accurate modeling of plant and soil hydraulic properties and knowledge of root distributions. Copyright 2002 by the American Geophysical Union. 2020-06-15T22:05:15Z 2020-06-15T22:05:15Z 2002 Artigo https://repositorio.inpa.gov.br/handle/1/19085 10.1029/2001JD000623 en Volume 107, Número 20, Pags. LBA 45-1-LBA 45-17 Restrito Journal of Geophysical Research Atmospheres
institution Instituto Nacional de Pesquisas da Amazônia - Repositório Institucional
collection INPA-RI
language English
topic Carbon Dioxide
Correlation Methods
Evapotranspiration
Forestry
Moisture
Soils
Tropics
Turbulence
Forest Canopy
Hydraulic Property
Seasonal Variation
Solar Radiation
Turbulent Mixing
Water Budget
Amazonas
Amazonia
Brasil
Manaus
South America
spellingShingle Carbon Dioxide
Correlation Methods
Evapotranspiration
Forestry
Moisture
Soils
Tropics
Turbulence
Forest Canopy
Hydraulic Property
Seasonal Variation
Solar Radiation
Turbulent Mixing
Water Budget
Amazonas
Amazonia
Brasil
Manaus
South America
Malhi, Yadvinder Singh
Energy and water dynamics of a central Amazonian rain forest
topic_facet Carbon Dioxide
Correlation Methods
Evapotranspiration
Forestry
Moisture
Soils
Tropics
Turbulence
Forest Canopy
Hydraulic Property
Seasonal Variation
Solar Radiation
Turbulent Mixing
Water Budget
Amazonas
Amazonia
Brasil
Manaus
South America
description This paper presents measurements of the energy and water budgets of a tropical rain forest near Manaus, Brazil, in central Amazonia, collected between September 1995 and August 1996. Fluxes of sensible and latent heat were measured using a three-dimensional eddy covariance system mounted above the forest canopy. Using a new approach to analysis of eddy covariance data, we found that the measured fluxes increased significantly when turbulent transport on timescales of 1 to 4 hours was taken into account. With this new analysis, the measured turbulent fluxes almost balanced the incoming net radiation, giving increased confidence in the accuracy of the measured fluxes. Of the 5.56 GJ m-2 yr-1 of solar radiation supplied over the year, 11% were reflected, 15% were lost as net thermal emission, 27% were transported through sensible heat convection, 46% used in evapotranspiration, and 0.5% were used; in net carbon fixation. Total annual evapotranspiration was calculated to be 1123 mm; accounting for 54% of total precipitation. Seasohality was an important influence: limited water availability during the dry season caused evapotranspiration to reduce by 50%. Total canopy conductance was linearly correlated to soil moisture content, with typical midday values ranging between 0.8 mol m-2 s-1 in the wet season and 0.3 mol m-2 s-1 in the dry season. Such seasonal behavior is likely to be prevalent in most tropical forest regions, and correct description of dry-season evapotranspiration will require accurate modeling of plant and soil hydraulic properties and knowledge of root distributions. Copyright 2002 by the American Geophysical Union.
format Artigo
author Malhi, Yadvinder Singh
author2 Pegoraro, Emiliano
Nobre, Antônio Donato
Pereira, Maria G.P.
Grace, John
Culf, Alistair D.
Clement, Robert J.
author2Str Pegoraro, Emiliano
Nobre, Antônio Donato
Pereira, Maria G.P.
Grace, John
Culf, Alistair D.
Clement, Robert J.
title Energy and water dynamics of a central Amazonian rain forest
title_short Energy and water dynamics of a central Amazonian rain forest
title_full Energy and water dynamics of a central Amazonian rain forest
title_fullStr Energy and water dynamics of a central Amazonian rain forest
title_full_unstemmed Energy and water dynamics of a central Amazonian rain forest
title_sort energy and water dynamics of a central amazonian rain forest
publisher Journal of Geophysical Research Atmospheres
publishDate 2020
url https://repositorio.inpa.gov.br/handle/1/19085
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score 11.653393