The presentation concerns similarity theories and scaling laws used to  parametrize turbulence in ABL. The special focus will be on stably stratified boundary layers which forms mostly over night due to surface radiative cooling.

Weakly stably stratified boundary layers are described under the Monin-Obukhov similarity theory (MOST), in which the characteristic length scale is the Obukhov length L, constructed based on turbulent momentum and heat fluxes. However, as the stratification increases the Monin-Obukhov theory describes boundary layer less well. Our work focuses on similarity theories provided by invariant solutions of a set of governing equations for turbulence statistics.  We present experimental verification of the derived formulas and show that they improve parametrization of the strongly stratified ABL.