Premium
Humidity measurements in the free troposphere using Raman backscatter
Author(s) -
Vaughan G.,
Wareing D. P.,
Thomas L.,
Mitev V.
Publication year - 1988
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.49711448406
Subject(s) - radiosonde , cirrus , troposphere , lidar , water vapor , tropopause , humidity , mixing ratio , materials science , environmental science , atmospheric sciences , hygrometer , relative humidity , raman scattering , raman spectroscopy , meteorology , remote sensing , optics , geology , physics
Abstract A lidar system has been developed to measure the mixing ratio of atmospheric water vapour using Raman scattering from water vapour and nitrogen. The system uses the third harmonic of a neodymium‐YAG laser at 354.7 nm, with interference filters to isolate the vibrational Raman bands. Humidity profiles extending from about 2 km to the tropopause have been obtained, with a resolution of 30 m vertically and 20 minutes in time below 5 km, and > 300m vertically and several hours in time above 10 km. Good agreement was found between the lidar profiles and those of coincident radiosondes. Distinctive layers in the humidity profiles are presented, and measurements in the vicinity of cirrus clouds indicate sharp transitions from supersaturation to saturation with respect to ice at the cloud boundary.