Estimating Buoyancy Heat Flux Using the Surface Renewal Technique over Four Amazonian Forest Sites in Brazil

Autor(es)

Zeri, Marcelo ^[1] ; Sa, Leonardo D. A. ^[2] ; Nobre, Carlos A. ^{[3, 4]}

Afiliação do(s) autor(es)

^[1] Inst Nacl Pesquisas Espaciais, Ctr Ciencia Sistema Terr, SP RJ, BR-12630000 Cachoeira Paulista, SP - Brazil

^[2] Inst Nacl Pesquisas Espaciais, Ctr Reg Amazonia, Belem, Para - Brazil

^[3] Minist Ciencia Tecnol & Inovacao, Secretaria Polit, Brasilia, DF - Brazil

^[4] Minist Ciencia Tecnol & Inovacao, Programas Pesquisa & Desenvolvimento, Brasilia, DF - Brazil

• Tipo de documento: Artigo Científico
• Fonte: BOUNDARY-LAYER METEOROLOGY; v. 149, n. 2, p. 179-196, NOV 2013.
• Citações Web of Science: 4

Resumo

The surface renewal (SR) method was applied for the first time to measurements of air temperature over four Amazonian forest sites and different seasons in order to obtain estimates of buoyancy heat flux. The required calibration of this method against eddy covariance resulted in a value for a specific parameter that is close to the range reported in other studies, contributing to the generalization of the SR method to different kinds of canopies. The comparison with fluxes obtained using the eddy covariance technique revealed a good match between the two methods for different sites, heights and seasons. Sites with high levels of non-stationarity in the signals of temperature and wind speed presented higher scatter in the regression with fluxes from eddy covariance. For a particular site with previously reported influence of low-frequency motions, the regression was only satisfactory, i.e., slope parameter close to unity and small offset, when oscillations with periods longer than 13 min were filtered out. The SR method has a great potential due to the simplicity of the instrumentation required. However, care should be taken when measuring under the influence of mesoscale motions, which can lead to high levels of non-stationarity, compromising the fundamental concepts of the SR theory. (AU)

• Processo FAPESP: 01/06908-7 - Interações entre radiação, nuvens e clima na Amazônia na transição entre as estações seca e chuvosa/LBA
• Beneficiário: Maria Assunção Faus da Silva Dias
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 11/04101-0 - Fluxos verticais de energia, escalares e momentum sobre superfícies vegetadas calculados pela técnica surface renewal
• Beneficiário: Luis Marcelo de Mattos Zeri
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado