Automatic detection of boundary layer by Micropulse Lidar (MPL)

Description

The planetary boundary layer (PBL) is a feature of the lower troposphere that restricts mixing between the surface and the free atmosphere aloft. Its top height is often on the order of 1 km above the surface, but varies according to weather conditions. It has proved difficult to incorporate into global climate models, in which an accurate PBL parameter would help to simulate the global transport and distribution of aerosols. Although the boundary is defined by a buoyantly stable temperature inversion, the aerosol lidar backscatter signal is a desirable proxy measurement due to the high temporal resolution of ground-based, upward-directed MPL data. A PBL detection algorithm based on the Haar wavelet covariance transform (Davis et al. 2000, Brooks 2003) has been developed for MPLNET backscatter data. This algorithm was evaluated during the ICEALOT research campaign of March–April 2008. It is now adapted for MPL sites in China, demonstrating its ability to detect the PBL in a wide variety of locations and conditions.