Mean vertical velocity and turbulence intensity inside and outside thermals

Abstract

Aircraft data from the Air Mass Transformation Experiment (AMTEX) are used to estimate mean vertical velocities and turbulence intensities of a field of convective elements (thermals) and its environment. Thermals are defined here by segments of the time series (which has first been high-pass filtered with a 5 km wavelength cutoff filter) where humidity exceeds half a standard deviation above the mean. Mixed layer normalization is used to generalize the results for application to simplified models of pollution dispersion from elevated sources.