author = "Saatchi, Sassan and Rodriguez, Ernesto and Denning, Scott and Lu, 
                         Lixin and Alvala, Regina Celia dos Santos and Dubayah, Ralph",
                title = "Measuring Vegetation Aerodynamic Roughness Over the Amazon Basin",
                 year = "2002",
         organization = "International LBA Scientific Conference, 2.",
             keywords = "METEOROLOGIA, Bacia Amaz{\^o}nica, Aspereza da 
                         superf{\'{\i}}cie, vegeta{\c{c}}{\~a}o, medi{\c{c}}{\~o}es, 
                         Regi{\~a}o Amaz{\^o}nica (Am{\'e}rica do Sul), Surface 
                         roughness, vegetation, measurement, Amazon region (South 
             abstract = "The aerodynamic roughness length (Z0)is an important parameter to 
                         determine the vertical gradients of mean wind speed and the 
                         conditions for momentum transfer over a vegetated or bare rough 
                         surface. Over vegetated surfaces, the aerodynamic roughness length 
                         has a simple one-to-one relationship with the rms height of the 
                         vegetation at the top of the canopy. Once this roughness length is 
                         determined for a surface, it does not change with wind speed, 
                         stability or stress. During the LBA experiment the Regional 
                         Atmospheric Modeling System (RAMS)with flexible horizontal and 
                         vertical resolution will be used in conjunction with other models 
                         to simulate the atmospheric circulation and trace gas 
                         concentration and transport at various scales. This model is 
                         suitable to determine the effect of surface roughness parameter at 
                         trace gas transport both at local level for LBA study areas and on 
                         at the regional level for the entire Amazon basin. In this paper, 
                         we present the estimation of this parameter from two sources: 
                         1)From a sample SRTM (Shuttle Radar Topography Mission)data over 
                         one of the LBA study areas. The cross correlation between two 
                         interferometric SRTM images will be used to estimate the rms 
                         height of the vegetation at 90 m resolution and relate that to 
                         aerodynamic roughness. This methodology will be applied to the 
                         entire SRTM data (when it becomes available)to estimate the 
                         roughness length over the basin. 2)Various statistical moments of 
                         the JERS-1 image mosaic in fusion with other regional data sets 
                         will be used in a semi-empirical model to estimate the vegetation 
                         roughness length over the entire basin at 1 km resolution. Both 
                         parameters will be integrated into the RAMS model to demonstrate 
                         the effect of spatially explicit roughness length on trace gas 
                         transport simulations and to test the impact of errors associated 
                         with the estimation process.",
  conference-location = "Manaus, Br",
      conference-year = "7-10 July 2002",
                label = "10218",
           targetfile = "9298.pdf",
        urlaccessdate = "22 jan. 2021"