  A combination of methods originating from non-stationary timeseries analysis
is applied to two datasets of near surface turbulence in order to gain insights
on the non-stationary enhancement mechanism of intermittent turbulence in the
stable atmospheric boundary layer (SBL). We identify regimes of SBL turbulence
for which the range of timescales of turbulence and submeso motions, and hence
their scale separation (or lack of separation) differs. Ubiquitous flow
structures, or events, are extracted from the turbulence data in each flow
regime. We relate flow regimes characterised by very stable stratification but
different scales activity to a signature of flow structures thought to be
submeso motions.
