Coherent structures detected in the unstable atmospheric surface layer above the Amazon forest

Author(s)

Dias Junior, C. Q. ^[1] ; Sa, L. D. A. ^[2] ; Pacheco, V. B. ^[3] ; de Souza, C. M. ^[1]

Affiliation

^[1] INPA, Manaus, Amazonas - Brazil

^[2] INPE, CRA, Belem, Para - Brazil

^[3] Univ Fed Amazonas, Manaus, Amazonas - Brazil

• Document type: Journal article
• Source: JOURNAL OF WIND ENGINEERING AND INDUSTRIAL AERODYNAMICS; v. 115, p. 1-8, APR 2013.
• Web of Science Citations: 10

Abstract

Some characteristics of the turbulence structure above primary forest localized in the south-western Amazon are analyzed. The data was collected in 60 m height meteorological tower erected in Rebio-Jaru Reserve, Brazil. The Morlet's wavelet is used to detect coherent structures (CS) ``ramp{''} time scales from turbulent virtual temperature data measured above forest, under day-time conditions. It is shown that there is a close relationship between time scale of the coherent structure (TCS) and the height to the inflection point in the mean wind speed profile (IP). A time scale associated with the IP is used to provide useful information on inside canopy penetration flow in order to be compared with the CS time-scale. The results show a very robust correlation between these two time scales (for 144 half-hourly data sets, a correlation coefficient value of 0.9 have been obtained). Such results provide new insights regarding shear instability and turbulent eddy characteristics above tall vegetation, in the surface roughness sub-layer (SRS). (c) 2013 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 01/06908-7 - Radiation, cloud and climate interactions in the Amazon during the Dry-To-Wet transition season/LBA
• Grantee: Maria Assunção Faus da Silva Dias
• Support Opportunities: Research Projects - Thematic Grants