Observational Investigation of the Statistical Properties of Surface-Layer Turbulence in a Suburban Area of São Paulo, Brazil: Objective Analysis of Scaling-Parameter Accuracy and Uncertainties

Statistical properties of turbulence, specifically variances of velocity components, temperature, water vapor, and carbon dioxide densities, are observationally characterized using turbulence measurements carried out between 2009 and 2017, at 25.4 m above surface in a suburban area in the metropolitan region of São Paulo (MRSP), Brazil. An objective analysis indicated that the best method to evaluate the zero-plane displacement ( d ), among five morphometric and anemometric methods is the temperature variance method. A new procedure based on the convergence of these methods is proposed to estimate the accuracy of the aerodynamic parameters. Normalized standard deviation of wind components and scalar properties are described by similarity functions based on Monin–Obukhov similarity theory. Uncertainties in d and Obukhov length are propagated to similarity functions derived for the MRSP and indicated uncertainties of up to 12% (22%) for wind components, 15% (23%) for temperature, 6% (23%) for water vapor and 11% (23%) for carbon dioxide densities during stable (unstable) conditions. By hypothesis testing it was demonstrated that the coefficients of normalized standard deviations of wind components for neutral stability conditions found at MRSP can be considered statistically equal to Roth’s urban averages (Q J R Meteorol Soc126:941–990, 2000), revealing the universal character of these functions. This agreement, added to other evidence, indicates that measurements used in the present study were performed in the inertial sublayer.