@InProceedings{SáBolzRamoRosa:2002:CoStOb,
               author = "S{\'a}, Leonardo Deane de Abreu and Bolzan, Mauricio Jose Alves 
                         and Ramos, Fernando Manuel and Rosa, Reinaldo Roberto",
                title = "Coherent structures observed immediately above Amazonian forest 
                         canopy in Rebio Jaru Reserve, Rondonia, Brazil",
                 year = "2002",
         organization = "International LBA Scientific Conference, 2.",
             keywords = "METEOROLOGIA.",
             abstract = "We used Morlet wavelet transform to detect coherent structures in 
                         wind velocity turbulent field above and within Amazon forest 
                         canopy. The data were measured in March 1999, during the 
                         wet-season of the Large Scale Biosphere Atmosphere Experiment in 
                         Amazonia (LBA), in southwestern part of Amazonia region. 
                         Measurements were made simultaneously at three different heights 
                         in a 60 meters micrometeorological tower located in the Biological 
                         Reserve of Jaru (10o 04{\"{\i}} S, 61o 56{\"{\i}} W), Brazil. 
                         The fast response wind speed measurements, sampled at 60 Hz rate, 
                         were made using Campbell three-dimensional sonic anemometers at 
                         the heights of 66 and 42 m (above the canopy), and 21 m (below the 
                         canopy). The results show that coherent structures are allways 
                         present at the 42m level, irrespectively of the time of the day. 
                         On the other hand, coherent structures are not ubiquous in the 
                         wind velocity turbulent signal measured at 66 and 21 m. During the 
                         day, the time-scale associated with the coherent structures 
                         detected at 42 m is of the order of 30 to 40 s. During the night, 
                         this time-scale grows up to values between 90 and 100 s. We 
                         congecture that these coherent structures are {"}role-type{"} 
                         structures asociated with inflexion point instability. They have a 
                         time-scale of the same of order of magnitude, and defined as t = 1 
                         / (d u / dz)|h, where du / dz |h is the mean horizontal wind 
                         velocity vertical gradient at h = 32 m, the mean height of the 
                         forest canopy.",
  conference-location = "Manaus, Br",
      conference-year = "7-10 July 2002",
                label = "10257",
           targetfile = "9338.pdf",
        urlaccessdate = "29 jun. 2024"
}