Field-Worthy UV Backscatter Lidar for Cirrus Studies

Cirrus clouds are an important element in atmospheric radiative transfer and impact both climate and climate change. The spatial coverage and frequency of cirrus clouds has been increasing in recent years. New instrumentation is needed to measure the occurrence and spatial extent of these clouds, in order to develop a database for climate modelers. This project will develop a compact ultraviolet backscatter lidar, which will utilize a state-of-the-art, all-solid-state ultraviolet laser for the transmitter. Compared to the existing MicroPulse Lidar, the instrument will provide better sensitivity and new capability for monitoring sub-visual cirrus clouds. Phase I demonstrated the requisite output energy and pulse repetition rate from an aircooled ultraviolet laser, which will serve as the heart of the new lidar. A modeling effort was conducted to demonstrate the expected increase in sensitivity arising from operating in the ultraviolet. Finally, the conceptual design for a field prototype Ultraviolet Backscatter Lidar was developed. In Phase II, the field prototype Ultraviolet Backscatter Lidar will be fabricated and tested, and then demonstrated at the Southern Great Plains Atmospheric Radiation Measurement site. The demonstration will include comparisons with the MicroPulse Lidar and the Raman Lidar, which already are deployed and operated at the site. Commercial Applications and Other Benefits as described by the awardee: A highly compact lidar system for the remote monitoring of cirrus clouds should fulfill an important near term need for a highly autonomous sensor for widespread use by monitoring networks. Other potential applications of the technology include the monitoring of natural and hazardous aerosols in the lower atmosphere, and the monitoring of tropospheric ozone and sulfur dioxide.