Twenty-four-hour Raman lidar water vapor measurements during the Atmospheric radiation Measurement program's 1996 and 1997 water vapor intensive observation periods

Prior to the Atmospheric Radiation Measurement program's first water vapor intensive observation period (WVIOP) at the Cloud and Radiation Testbed sit e near Lament, Oklahoma, an automated 24-h Raman lidar was delivered to the site. This instrument, which makes high-resolution measurements of water v apor both spatially and temporally, is capable of making these measurements with no operator interaction (other than initial startup) for days at a ti me. Water vapor measurements collected during the 1996 and 1997 WVIOPs are discussed here, illustrating both the nighttime and daytime capabilities of this system. System characteristics, calibration issues, and techniques ar e presented. Finally, detailed intercomparisons of the lidar's data with th ose from a microwave radiometer, radiosondes, an instrumented tower, a chil led mirror flown on both a tethersonde and kite, and measurements from airc raft are shown and discussed, highlighting the accuracy and stability of th is system for both nighttime and daytime measurements.