Please use this identifier to cite or link to this item: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1055915
Title: Canopy-scale biophysical controls of transpiration and evaporation in the Amazon Basin.
Authors: MALLICK, K.
TREBS, I.
BOEGH, E.
GIUSTARINI, L.
SCHLERF, M.
DREWRY, D. T.
HOFFMANN, L.
RANDOW, C. von
KRUIJT, B.
ARAUJO, A.
SALESKA, S.
EHLERINGER, J. R.
DOMINGUES, T. F.
OMETTO, J. P. H. B.
NOBRE, A. D.
MORAES, O. L. L. de
HAYEK, M.
MUNGER, J. W.
WOFSY, S. C.
Affiliation: KANISKA MALLICK, Luxembourg Institute of Science and Technology
IVONNE TREBS, Luxembourg Institute of Science and Technology
EVA BOEGH, Roskilde University
LAURA GIUSTARINI, Luxembourg Institute of Science and Technology
MARTIN SCHLERF, Luxembourg Institute of Science and Technology
DARREN DREWRY, California Institute of Technology
LUCIEN HOFFMANN, Luxembourg Institute of Science and Technology
CELSO VON RANDOW, INPE
BART KRUIJT, Wageningen University and Research Centre
ALESSANDRO CARIOCA DE ARAUJO, CPATU
SCOTT SALESKA, University of Arizona
JAMES R. EHLERINGER, University of Utah
TOMAS F. DOMINGUES, USP
JEAN PIERRE H. B. OMETTO, INPE
ANTONIO D. NOBRE, INPE
OSVALDO LUIZ LEAL DE MORAES, Centro Nacional de Monitoramento e Alertas de Desastres Naturais
MATTHEW HAYEK, Harvard University
WILLIAM MUNGER, Harvard University
STEVE WOFSY, Harvard University.
Date Issued: 2016
Citation: Hydrology and Earth System Science Discussions, 27 Jan. 2016.
Description: Canopy and aerodynamic conductances (gC and gA) are two of the key land surface biophysical variables that control the land surface response of land surface schemes in climate models. Their representation is crucial for predicting transpiration (?ET) and evaporation (?EE) flux components of the terrestrial latent heat flux (?E), which has important implications for global climate change and water resource management. By physical integration of radiometric surface temperature (TR) into an integrated framework of the Penman?Monteith and Shuttleworth?Wallace models, we present a novel approach to directly quantify the canopy-scale biophysical controls on ?ET and ?EE over multiple plant functional types (PFTs) in the Amazon Basin. Combining data from six LBA (Large-scale Biosphere-Atmosphere Experiment in Amazonia) eddy covariance tower sites and a TR-driven physically based modeling approach, we identified the canopy-scale feedback-response mechanism between gC, ?ET, and atmospheric vapor pressure deficit (DA), without using any leaf-scale empirical parameterizations for the modeling. The TR-based model shows minor biophysical control on ?ET during the wet (rainy) seasons where ?ET becomes predominantly radiation driven and net radiation (RN) determines 75 to 80?% of the variances of ?ET. However, biophysical control on ?ET is dramatically increased during the dry seasons, and particularly the 2005 drought year, explaining 50 to 65?% of the variances of ?ET, and indicates ?ET to be substantially soil moisture driven during the rainfall deficit phase. Despite substantial differences in gA between forests and pastures, very similar canopy?atmosphere "coupling" was found in these two biomes due to soil moisture-induced decrease in gC in the pasture. This revealed the pragmatic aspect of the TR-driven model behavior that exhibits a high sensitivity of gC to per unit change in wetness as opposed to gA that is marginally sensitive to surface wetness variability. Our results reveal the occurrence of a significant hysteresis between ?ET and gC during the dry season for the pasture sites, which is attributed to relatively low soil water availability as compared to the rainforests, likely due to differences in rooting depth between the two systems. Evaporation was significantly influenced by gA for all the PFTs and across all wetness conditions. Our analytical framework logically captures the responses of gC and gA to changes in atmospheric radiation, DA, and surface radiometric temperature, and thus appears to be promising for the improvement of existing land?surface?atmosphere exchange parameterizations across a range of spatial scales.
Thesagro: Climatologia
Evaporação
NAL Thesaurus: Amazonia
Keywords: Transpiração
DOI: 10.5194/hess-2015-552
Type of Material: Artigo de periódico
Access: openAccess
Appears in Collections:Outras publicações (CPATU)

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