A New Concept For Calculating the Height of Planetary Boundary Layer From Lidar Returns Using a Spatial Variance Algorithm

There are a wide variety of different methods to determine the Planetary Boundary Layer (PBL) from lidar data. All of these methods have limited applicability. This study presents a new concept of retrieving the PBL height from single lidar returns. The new algorithm is based on a spatial variance algorithm. This concept is introduced in two theoretical cases as well as two real situations. In this study, two time-dependant lidar datasets are used to perform computations for the variance algorithm along with derivative, logarithmic derivative and threshold algorithms. The results obtained using all the methods are compared in different representations and also compared with boundary layer height obtained form independent potential temperature profile measurements. The results are then used for further analysis of PBL height in larger time-scale using the well established Deardorff algorithm. Due to the simplicity of this new approach, it could be used for automated determination of PBL height and would be a valuable option for other algorithms.