Proposal of a new autocorrelation function in low wind speed conditions

•We propose a new mathematical expression to describe the meandering phenomenon.•We employ wind data measured in a nocturnal PBL to obtain experimental ACF.•The new ACF satisfactorily represents the negative lobes of the meandering phenomenon.

In this study a new mathematical expression to describe the observed meandering autocorrelation functions in low-wind speed is proposed. The analysis utilizes a large number of best fit curves to show that the proposed theoretical function well reproduces the general form and the negative lobes characterizing the experimental meandering autocorrelation function. Further, the good agreement of the measured autocorrelation curves with the proposed algebraic autocorrelation function allows to calculate the magnitudes of the meandering period and of the loop parameter. The results agree with the values presented and discussed in the literature. Therefore, the new formulation describing experimental meandering autocorrelation functions can be used to simulate the dispersion of contaminant during low wind episodes and to determine relevant meandering parameters.