Author(s)

S.M. Joffre & M. Kangas

Abstract

Simple diagnostic expressions for the stable and unstable atmospheric boundary layer height S.M. Joffre & M. Kangas Finnish Meteorological Institute, Finland Abstract We present here a new heuristic framework for the variability of the atmospheric boundary layer (ABL) height h based on an extended concept of the similarity theory retaining non-local effects. Based on several sets of well-known data (Wangara, JASIN, ICE-77), the locus of variability of h in the phase-space determined from this similarity framework points to a new combination for the most relevant scales affecting the ABL height. We show that the most likely length scales to explain the variability of the ABL height are the classical Monin- Obukhov length L and the background static stratification scale L=u^/N, where u* is the friction velocity and TV the Brunt- Vaisala frequency above the ABL. This concept is applied to a new set of data obtained above a high-latitude forested site, i.e., very different from the a

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