Vertical Profiles of the Structure Parameter of Temperature in the Stable, Nocturnal Boundary Layer

Vertical profiles of the structure parameter of temperature C T 2 in the stable, nocturnal boundary layer (NBL) have been obtained with the analytic models described by Nieuwstadt (1984, 1985) and Sorbjan (1986) and the numerical model of Duynkerke and Driedonks (1987). These theoretical profiles are compared with observed profiles from the meteorological mast at Cabauw, The Netherlands. From the observations, it is found that C T 2 is large in the surface layer and small at the top of the NBL. Observations during nights with moderate geostrophic winds or during the first few hours of nights with a high geostrophic wind show a continuous decrease of C T 2 from the surface layer to the top of the NBL. Observations made later on nights with a high geostrophic wind show the development of a maximum of C T 2 at about three quarters of the NBL. From the comparison with the models, we conclude that the observed profiles are most satisfactorily described by the model of Duynkerke and Driedonks.