A comparison of methods to estimate the height of stable boundary layer over a temperate grassland

The development and structure of the nocturnal stable boundary layer (SBL) were analyzed using atmospheric soundings obtained during the field experiment for CASES-99 (Cooperative Atmosphere-Surface Exchange Study-1999) over temperature grassland in Kansas, USA. The present analysis of the nocturnal SBL heights was made using inversion strength in the vertical profiles of potential temperature, which was determined from the residual layer with a relatively uniform potential temperature. The growth of the nocturnal SBL and the change in its structure were analyzed using the time series plots of the SBL heights and by estimating the curvature of the vertical profile of potential temperature. The performance of the inversion strength method in the determination of the nocturnal SBL height was assessed by comparing the SBL height with the ones by a low-level jet, the Brunt–Väisälä frequency and the critical wind shear. There exists a relatively high correlation between the SBL heights of the inversion strength and the critical wind shear.