Investigations on convective boundary layer turbulence using SODAR data

Acoustic sounding (SODAR) data collected in convective conditions were analysed to estimate high order
statistics of the vertical velocity in the lower half of the Convective Boundary Layer (CBL). Limitations of the
instrumentation system were assessed and it turned out that spatial and temporal fi ltering have little effect on
skewness and kurtosis, and do not prevent a reliable evaluation of these parameters, provided that a suffi ciently
long time period is analysed. Vertical profi les of skewness are grouped into two broadly defi ned classes, one
which increases almost linearly with height and the other which shows a constant-with-height behaviour. Both
behaviours are shown to be consistent with different parameterisations used in literature. Kurtosis profi les are
found to be fairly well described adopting a quadratic relationship between skewness and kurtosis, provided that
the correct parameterisation of skewness is used.