Eddy correlation measurements of energy partition for Amazonian forest

SHUTTLEWORTH, JAMES W; GASH, JOHN C; LLOYD, COLIN R; MOORE, CHRISTOPHER J; Roberts, John P.; Filho, Arí de Oliveira Marques; Fisch, Gilberto; Filho, Vicente de Paula Silva; Ribeiro, Maria de Nazaré Góes; MOLION, LUIZ CB; Sa, Leonardo Deane Abreu; CARLOS, J; Nobre, Antônio Donato; CABRAL, OSVALDO MR; Patel, Sukaran Ram; Moraes, Jean

doi:10.1256/smsqj.46620

Cited by 34 publications

(31 citation statements)

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“…This filtering process also explains why stable regions have a higher intermittency level than unstable ones. We remark that such eddy-filter character of forested canopies has already been observed by other authors [22,23,24].…”

Section: Wind Velocity Datasupporting

confidence: 86%

Atmospheric turbulence within and above an Amazon forest

Ramos

Bolzan

Sá

et al. 2004

Physica D: Nonlinear Phenomena

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In this paper, we discuss the impact of a rain forest canopy on the statistical characteristics of atmospheric turbulence. This issue is of particular interest for understanding on how the Amazon terrestrial biosphere interact with the atmosphere. For this, we used a probability density function model of velocity and temperature differences based on Tsallis' non-extensive thermostatistics. We compared theoretical results with experimental data measured in a 66 m micrometeorological tower, during the wet-season campaign of the Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA). Particularly, we investigated how the value of the entropic parameter is affected when one moves into the canopy, or when one passes from day/unstable to night/stable conditions. We show that this new approach provides interesting insights on turbulence in a complex environment such as the Amazon forest.

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Section: Wind Velocity Datasupporting

confidence: 86%

Atmospheric turbulence within and above an Amazon forest

Ramos

Bolzan

Sá

et al. 2004

Physica D: Nonlinear Phenomena

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“…Canopy resistance of this forest increases in the afternoon, primarily in response to increasing D which has a 'feedback influence' on stomatal closure (see Jarvis, 1981;Murphy etal., 1981;McNaughton and Jarvis, 1983) and to temporary water deficit (Hinckley etal., 1978). The diurnal pattern and magnitudes of r,, reported here, are similar to those observed over Douglas fir (McNaughton and Black, 1973) loblolly pine (Murphy et al, 1981), and over an Amazonian forest (Shuttleworth et al, 1984). McNaughton and Jarvis (1983) and Jarvis (1985) introduced the concept of coupling between the canopy and the atmosphere in terms of the Omega factor, given by: 0, = (4~ + 1)/b/~ + 1 + r,/rJ 9 where s is the slope of the temperature-dependent saturation vapor pressure curve and y is the psychrometric constant.…”

Section: Aerodynamic and Canopy Resistances The Omega Factorsupporting

confidence: 80%

“…Similar midday values of p have been observed over a forest at Marmot Creek in Alberta, Canada (Storr er al., 1970) over a Southeastern loblolly pine plantation (Murphy et al, 1981) and over an Amazonian forest (Shuttleworth et al, 1984). Black and McNaughton (1971) and McCaughey (198513) in Ontario, respectively.…”

Section: The Bowen Ratiomentioning

confidence: 99%

Eddy fluxes of CO2, water vapor, and sensible heat over a deciduous forest

Verma

Baldocchi

Anderson

et al. 1986

Boundary-Layer Meteorol

209

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Fluxes of CO,, latent heat and sensible heat were measured above a fully-leafed deciduous forest in eastern Tennessee with the eddy correlation technique. These are among the first reported observations over such a surface. The influences of solar radiation, vapor pressure deficit and the aerodynamic and canopy resistances on these mass and energy exchanges are examined. Following a concept introduced by McNaughton and Jarvis (1983). examination of our data suggest that the water vapor exchange of a deciduous forest is not as strongly coupled with net radiation as is that of agricultural crops. The degree of decoupling is smaller than in the case of a coniferous forest. This difference may be attributable in part to the greater aerodynamic resistance to water vapor transfer in a deciduous forest. It appears that the concept of decoupling may be extended to the CO, exchange of a deciduous forest as well.

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“…In this study, a time constant of 375 s was used in the digital filter. Some further details of these instruments and their use are given by Shuttleworth et al (1984). In the version of the microprocessor program used in this study, the wind velocity and its variance at right angles to the direction of the mean wind were not recorded.…”

Section: Instrumentationmentioning

confidence: 99%