Active and passive remote sensing for monitoring the planetary boundary layer height

摘要

The planetary boundary layer (PBL) is the lowest part of the atmosphere directly influenced by its contact with the land surface and it usually responds to changes in surface forcing in a time scale of an hour or less. Continuous monitoring of its height is highly important for atmospheric and environmental sciences. This work presents continuous monitoring of the PBL height (PBLH) using active (lidar and ceilometer) and passive (microwave radiometer, MWR) remote sensing instruments. Both methodologies are suitable for continuous monitoring of the planetary boundary layer under almost all weather conditions during daytime but, at nighttime ceilometer- and lidar-based techniques are limited due to the overlap of the instruments and MWR-based techniques are not always applicable due to lack of convection. The wavelet covariance transform method is applied to lidar and ceilometer data, optimizing in each case the detection of the PBL during daytime. Independent estimates using the parcel method with temperature profiles from a co-located passive MWR are used for comparison. Validation of both active and passive remote sensing techniques is performed at times when radiosoundings are available.