Understanding water and energy fluxes in the Amazonia: Lessons from an observation-model intercomparison.

Autor:	Restrepo-Coupe N; Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA.; School of Life Sciences, University of Technology Sydney, Ultimo, NSW, Australia., Albert LP; Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA.; Biology Department, West Virginia University, Morgantown, WV, USA., Longo M; Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA.; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA., Baker I; Colorado State University, Atmospheric Science, Fort Collins, CO, USA., Levine NM; Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA.; College of Letters, Arts, and Science, University of Southern California, Los Angeles, CA, USA., Mercado LM; University of Exeter, College of Life and Environmental Sciences, Exeter, Devon, UK.; Centre for Ecology and Hydrology, Wallingford, Oxfordshire, UK., da Araujo AC; Embrapa Amazônia Oriental, Belém, Pará, Brazil.; Programa LBA, Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus, Amazonas, Brazil., Christoffersen BO; Department of Biology, University of Texas Rio Grande Valley, Edinburg, TX, USA.; Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, USA., Costa MH; Department of Agricultural Engineering, Federal University of Vicosa, Vicosa, Mato Grosso, Brazil., Fitzjarrald DR; University at Albany SUNY, Albany, NY, USA., Galbraith D; School of Geography, University of Leeds, Leeds, UK., Imbuzeiro H; Department of Agricultural Engineering, Federal University of Vicosa, Vicosa, Mato Grosso, Brazil., Malhi Y; Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, UK., von Randow C; National Institute for Space Research (INPE), Center for Earth Systems Science, São José dos Campos, São Pablo, Brazil., Zeng X; Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ, USA., Moorcroft P; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA., Saleska SR; Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA.
Jazyk:	angličtina
Zdroj:	Global change biology [Glob Chang Biol] 2021 May; Vol. 27 (9), pp. 1802-1819. Date of Electronic Publication: 2021 Mar 03.
DOI:	10.1111/gcb.15555
Abstrakt:	Tropical forests are an important part of global water and energy cycles, but the mechanisms that drive seasonality of their land-atmosphere exchanges have proven challenging to capture in models. Here, we (1) report the seasonality of fluxes of latent heat (LE), sensible heat (H), and outgoing short and longwave radiation at four diverse tropical forest sites across Amazonia-along the equator from the Caxiuanã and Tapajós National Forests in the eastern Amazon to a forest near Manaus, and from the equatorial zone to the southern forest in Reserva Jaru; (2) investigate how vegetation and climate influence these fluxes; and (3) evaluate land surface model performance by comparing simulations to observations. We found that previously identified failure of models to capture observed dry-season increases in evapotranspiration (ET) was associated with model overestimations of (1) magnitude and seasonality of Bowen ratios (relative to aseasonal observations in which sensible was only 20%-30% of the latent heat flux) indicating model exaggerated water limitation, (2) canopy emissivity and reflectance (albedo was only 10%-15% of incoming solar radiation, compared to 0.15%-0.22% simulated), and (3) vegetation temperatures (due to underestimation of dry-season ET and associated cooling). These partially compensating model-observation discrepancies (e.g., higher temperatures expected from excess Bowen ratios were partially ameliorated by brighter leaves and more interception/evaporation) significantly biased seasonal model estimates of net radiation (R n ), the key driver of water and energy fluxes (LE ~ 0.6 R n and H ~ 0.15 R n ), though these biases varied among sites and models. A better representation of energy-related parameters associated with dynamic phenology (e.g., leaf optical properties, canopy interception, and skin temperature) could improve simulations and benchmarking of current vegetation-atmosphere exchange and reduce uncertainty of regional and global biogeochemical models. (© 2021 John Wiley & Sons Ltd.)
Databáze:	MEDLINE
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