An experimental case study of the mean and turbulent characteristics of the vertical structure of the atmospheric boundary layer over the sea

Abstract

The main characteristics of the mean and turbulent vertical structure of the Marine Atmospheric Boundary Layer (MABL) up to the height of 500 m are examined for an experimental case, using both remote and in situ sensing instrumentation. The observations indicate the existence of a very stable surface layer up to the height of 150-200 m followed by slightly stable to neutral conditions at higher levels, while a Low-Level Jet (LLJ) is developed, on the top of the intense surface based inversion. High values of the variance of the vertical wind component are observed at levels above the LLJ core, presumably associated with the shear forcing close to the LLJ. The plausible mechanism for the development of the LLJ is the inertial oscillation due to the frictional decoupling over the sea, which is associated with the strong stability of the MABL lower layer.