Estudo da influência das estruturas coerentes e da rugosidade na estimativa de fluxos turbulentos sobre 0 Pantanal

Bolzan, Maurı́cio José Alves

doi:10.1590/s0102-261x1999000200014

Cited by 2 publications

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“…The results from the ATTO-CLAIRE experiment (IOP-1/2012), are in agreement with those described by Wallace (1972), Hussain (1986), Katul et al (1997, according to which, when there are variations in stability conditions, there is an influence of time on the duration of coherent structures. Therefore, this study demonstrated a robustness in the identifcation of coherent structures denominated as "rolls" for the studied flux, as was also demonstrated by Raupach & Thom (1981), Raupach et al (1996, Bolzan (2000) and Bolzan & Vieira (2006).…”

Section: Discussionsupporting

confidence: 80%

“…The raw data of 10 Hz, 4 Hz, and 1 Hz were submitted to calculation of averages of the three wind components (u, v, and w), as well as the variance, covariance, asymmetries (skewnesses ), and kurtosis, using the rate Z/h = 2.08 in the rough sub-layer of the forest in ATTO. The data were normalized to infer parameters such as: the average wind with height of treetops (u/u(h)); momentum flux, with the (u * ) friction wind velocity (u v /(u 2 * )), which at the top of the tower is equivalent to (u * ) = (−u v top ) 1/2 ; for the height of the h = 80-metre tower, the standard deviations, σ u = (u 2 ) 1/2 /u * and σ w = (w 2 ) 1/2 /u * ; the correlation coefficient between u and w, −r + uw = −u w /(σ u σ w ); the asymmetries (skewnesses) of u and w, Sk u and Sk w (e.g., w 3 /σ 3 w ); and finally, the kurtosis of u and w, (e.g., w 4 /σ 4 w ), Kaimal & Finnigan (1994), Bolzan (2000), Kruijt et al (2000).…”

Section: Study Areamentioning

confidence: 99%

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A Brief Observation of the Formation of Coherent Structures and Turbulence Over a Rain Forest Area in Central Amazônia: The Atto-Claire/Iop – 1/2012 Experiment

Lima¹,

Silva²,

Bolzam³

et al. 2017

Rev. Bras. Geof.

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ABSTRACT. This work used micrometeorological measurements of temperature and wind in order to characterize the turbulence due to wind in a terra firme forest in central Amazonia as part of the ATTO-CLAIRE / IOP-1 (2012) (Amazon Tall Tower Observatory – Cooperative LBA Airborne Regional Experiment / Intensive Observation Period – 2012 / LBA – Large Scale Biosphere-Atmosphere Experiment in the Amazon). This research was conducted at the Uatumã ATTO Sustainable Development Reserve in the State of Amazonas, Brazil, from February to September, 2012, and used data from February 26 to September 07, 2012, dates that partially encompass the wet and dry seasons, respectively. The ATTO site has 5 towers: one that is 320m, and four that are 80 m in height, and this research was conducted on an 80 m triangular tower. A total of ten 3D and 2D ultrasonic anemometers were installed on the tower, and the importance of these instruments used for flux measurements is also evident when taking into account the fact that the dissemination and diffusion of seeds and chemical composts in the forest happens through the action of turbulent fluxes. In order to understand the wind profile, the inflection point of the wind velocity, and coherent structures (ECs) and local turbulence, box-plot diagrams, quadrant analyses, wavelet potential spectrum, and energy potential analyses were conducted. The turbulence characterized at the ATTO had a roll or ramp structure during the study period, which represents favorable conditions for the maintenance of the forest during the wet and dry seasons in the Central Amazon. Keywords: inflection point, ramp, wavelet, turbulence. RESUMO. Este trabalho faz uso de medidas micrometeorológicas de temperatura e vento, com finalidade de caracterizar a turbulência aerotransportada em uma floresta de terra firme na Amazônia Central, realizadas no experimento ATTO-CLAIRE / IOP-1 (2012) (Amazon Tall Tower Observatory – Cooperative LBA Airborne Regional Experiment / Intensive Observation Period – 2012 / LBA – Large Scale Biosphere-Atmosphere Experiment in Amazônia), no sítio do ATTO, na Reserva de Desenvolvimento Sustentável do Uatumã – AM (Brasil) nos meses de fevereiro a setembro de 2012, com dados analisados a partir do dia 26 de fevereiro de 2012 até o dia 7 de setembro de 2012, entre as estações úmida e seca na Amazônia Central, no complexo de torres altas composta de 5 (cinco) torres; uma de 320 m e 4 (quatro) de 80 m. Este trabalho foi realizado na torre triangular (80 m). Foram instalados 10 (dez) anemômetros ultrassônicos de 3D e 2D. Equipamentos necessários em método de fluxos, visto que, a disseminação e difusão de sementes e compostos químicos da floresta, faz-se também por fluxos turbulentos. Para compreensão do perfil de vento, ponto de inflexão do perfil da velocidade do vento, estruturas coerentes e a turbulência local, para tal desenvolveu-se a partir dos dados processados, diagrama de caixa (box-plot ), análise de quadrantes, espectro de potência em ondeletas, espectro de energia. A turbulência caracterizada no ATTO, foi de estruturas do tipo “rolo” ou rampa, para o período estudado, condições favoráveis para manutenção da floresta em período úmido-seco na Amazônia Central.Palavras-chave: ponto de inflexão, rampa, ondeleta, turbulência.

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Section: Discussionsupporting

confidence: 80%

Section: Study Areamentioning

confidence: 99%

A Brief Observation of the Formation of Coherent Structures and Turbulence Over a Rain Forest Area in Central Amazônia: The Atto-Claire/Iop – 1/2012 Experiment

Lima¹,

Silva²,

Bolzam³

et al. 2017

Rev. Bras. Geof.

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“…2003). This is achieved by viewing a threedimensional diagram in a series of chart-temporal, where the ordinate axis locates the frequency scale, the abscissa the time scale, and the third axis the intensity of energy (usually represented by color spectrum) Bolzan, (2000Bolzan, ( , 2006. Thus the term wavelet refers to a set of functions with the form of small waves generated by dilation, ψ (t) → ψ (2t), and translations, ψ (t) →ψ (t +1) a function generator based on simple ψ (t), called wavelet-mother, (Bolzan, 2006).…”

Section: Wavelet Transformedmentioning

confidence: 99%

On the characteristics of formation of coherent structure and turbulence in a dense forest of land measuring up to 80m in height: Project ATTO - CLAIRE - IOP1-2012

Lima

Ferreira

Pietzsch

et al. 2013

13th International Congress of the Brazilian Geophysical Society &Amp; EXPOGEF, Rio De Janeiro, Brazil, 26–29 August 2013

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The characterization of formation of coherent structure by means of momentum transport and heat, above and within the canopy of an upland forest, is described here using as primary focus turbulent flow the vorticity of the flow through the quadrant analysis and the Morlet wavelet transformed into power spectrum for the temperature. The identification of vorticity and coherent structure for the studied levels were observed, with the "background" tower of 84 m, the intensive observation period -1 (IOP-1/2012), in the forest of SDR -Uatumã -AM -Brazil.

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Estudo da influência das estruturas coerentes e da rugosidade na estimativa de fluxos turbulentos sobre 0 Pantanal

Cited by 2 publications

References 0 publications

A Brief Observation of the Formation of Coherent Structures and Turbulence Over a Rain Forest Area in Central Amazônia: The Atto-Claire/Iop – 1/2012 Experiment

A Brief Observation of the Formation of Coherent Structures and Turbulence Over a Rain Forest Area in Central Amazônia: The Atto-Claire/Iop – 1/2012 Experiment

On the characteristics of formation of coherent structure and turbulence in a dense forest of land measuring up to 80m in height: Project ATTO - CLAIRE - IOP1-2012

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