Calibration of Raman lidar water vapor profiles by means of AERONET photometer observations and GDAS meteorological data

Abstract

Abstract. We present a practical method to continuously calibrate Raman lidar observations of the water vapor mixing ratio and an instrumental uncertainty of 0.72 g kg −1). To check the quality of the water 10 vapor calibration, the water vapor mixing ratio profiles from the simultaneous nighttime observations with Raman lidar and Vaisala radiosonde sounding are compared. The correlation of the water vapor mixing ratios from these two instruments is determined by using all of the 19 simultaneous nighttime measurements during CyCARE. Excellent agreement with the slope of 1.01 and the R 2 of 0.99 is found. One example is presented to demonstrate the full potential of a well calibrated Raman lidar.The relative humidity profiles from lidar, GDAS (simulation) and radiosonde are compared. It is found that the combination of 15 water vapor mixing ratio and GDAS temperature profiles allow us to derive relative humidity profiles with good accuracy.

Water Vapor Calibration: Using a Raman Lidar and Radiosoundings to Obtain Highly Resolved Water Vapor Profiles

“…While this method is completely independent of other instruments, it introduces more components to the lidar and more effort during data acquisition. The second method uses humidity profiles from external instrumentation such as radiosondes (e.g., [16,17]), microwave (e.g., [18,19] or photometer data (e.g., [20] for calibration. In addition, a hybrid technique, employing both a tungsten lamp and radiosonde, has also been introduced [21].…”