Study of the overturning length scales at the Spanish planetary boundary layer

Abstract

Abstract. The focus of this paper is to analyse the behaviour of the maximum Thorpe displacement (d T ) max and the Thorpe scale L T at the atmospheric boundary layer (ABL), extending previous research with new data and improving our studies related to the novel use of the Thorpe method applied to ABL. The maximum Thorpe displacements vary between −900 and 950 m for the different field campaigns. The Thorpe scale L T ranges between 0.2 and 680 m for the different data sets which cover different stratified mixing conditions (turbulence shear-driven and convective regions). We analyse the relationship between (d T ) max and the Thorpe scale L T and we deduce that they verify a power law. We also deduce that there is a difference in exponents of the power laws for convective conditions and sheardriven conditions. These different power laws could identify overturns created under different mechanisms.