Observing Planetary Boundary Layer (PBL) Water Vapor Profiles with MicroPulse Differential Absorption Lidar (MPD)

The National Center for Atmospheric Research (NCAR) and Montana State University collaboratively developed a small network of five MicroPulse Differential absorption lidars (MPDs) designed for water vapor remote sensing. This innovation represents a significant advance in eye-safe, unattended, diode laser-based technology for measuring water vapor. The MPDs provide continuous vertical profiles of absolute humidity with high vertical (150 m) and temporal resolution (5 min) in the lower troposphere (extending up to 4-6 km AGL). The MPDs have been successfully deployed during field campaigns across diverse locations, including Argentina, Taiwan, Kansas and Colorado.

Water vapor profiles will be shown for multiple atmospheric phenomena as they pass over the MPDs. Among the phenomena are PBL development, gust fronts, cold fronts, horizontal convective rolls, bores and convection initiation. To offer a comprehensive depiction of these atmospheric features, supplementary data such as radar reflectivity and radial velocity are utilized to illustrate the clear-air mesoscale structures. Details of the PBL wind profiles will be shown with wind profiler data, while thermodynamic profiles will be presented using radiosondes. With the combined use of supplementary data and MPD water vapor profiles during passages of different atmospheric phenomena, a full representation of the content, depth, evolution, and variability of water vapor within the lower troposphere will be shown.