Wide-range sounding of free-tropospheric water vapor with a differential-absorption lidar (DIAL) at a high-altitude station.
A differential absorption lidar (DIAL) system has been developed for the measurement of water vapor throughout the free troposphere [3 to 12 km above sea level (asl.)] with high vertical resolution varied from 50 m next to the ground to 300 m above an altitude of 10 km. The system was installed at the Schneefernerhaus high-altitude research station (2675 m asl., Zugspitze, Germany). The DIAL system is based on a tunable single-mode laser system with a high pulse energy of currently 250 mJ and a repetition rate of 20 s(-1). For lidar operation with energies typically between 100 mJ and 150 mJ and an integration time of 1000 s (10000 laser shots for both DIAL wavelengths) a vertical range of at least 10 km has been demonstrated even under dry conditions and during daytime, while daytime measurements up to 12 km have been possible under humid conditions. The system was intercompared with radiosondes, which suggests an agreement within 5% in a major part of the operating range. Further improvements are planned in the upper troposphere to approach the accuracy requirements needed in climate research.
Vogelmann
Hannes
H
Institut für Meteorologie und Kimaforschung, Forschungszentrum Karlsruhe, Kreuzeckbahnstr. 19, Garmisch-Partenkirchen, Germany. hannes.vogelmann@imk.fzk.de
Trickl
Thomas
T