First measurements of upper tropospheric and lower stratospheric water vapour mixing ratios using the Purple Crow Raman-scatter Lidar.

摘要

The Purple Crow Lidar's large power-aperture product allows measurements of upper tropospheric and lower stratospheric water vapour mixing ratio measurements to be made on a routine basis. Typical lidar water vapour mixing ratios in the lower stratosphere are near 4 ppmv, which compares well with the other studies using balloon-borne frost-point hygrometers. A preliminary analysis of the seasonal variations in the measured stratospheric water vapour mixing ratios also suggests that the summer water vapour mixing ratios are larger than the spring water vapour mixing ratios, which has also been detected by Oltmans and Hofmann over Boulder, CO. High-resolution tropospheric observations on the nights of May 10, June 26, and July 11, 1999 are also presented and discussed, particularly in regards to the convective boundary layer, the capping inversion, and moving weather fronts.