Measurement of tropospheric temperature and aerosol extinction using high spectral resolution lidar

A high spectral resolution Rayleigh-Mie lidar system capable of measuring relative temperature and aerosol profiles in the troposphere has been developed. The use of a narrowband laser transmitter along with an atomic vapor cell as a variable width bandstop filter allows for the separation of molecular and aerosol scattering signals. Using two of these filters with different widths and a newly developed lidar inversion method it is possible to determine relative temperature, pressure, and density profiles of the troposphere. This separation also makes a quantitative measurement of aerosol extinction coefficient profiles possible.; In principle, the information required in addition to the lidar signals for determining atmospheric and aerosol properties with this Rayleigh-Mie lidar is: the theoretical Rayleigh-Brillouin spectrum for scattering of narrow bandwidth laser light, independent measurements of the filter transmission functions, the assumption that the atmosphere acts as an ideal gas in hydrostatic equilibrium, and an approximate atmospheric pressure at one reference altitude. Profiles of the tropospheric state variables of temperature, pressure, and density are determined from signals averaged over 20 minutes. Once profiles of the atmospheric variables are determined, the aerosol extinction coefficient profiles are calculated.; A systematic offset in the lidar temperature profiles is seen however in practice when compared to balloon sonde measurements. Further laboratory experiments have established that the systematic offset is real and is consistent between laboratory and field measurements. This repeatable offset can be eliminated by normalizing the temperature at a reference altitude to an independently measured or estimated value.; The development and implementation of this high spectral resolution lidar and the first simultaneous measurements of tropospheric temperature and aerosol profiles from 0.2 km to 8 km are presented. The precision at 1 km altitude is {dollar}pm{dollar}10 K for temperature measurement, {dollar}pm{dollar}3% for backscatter ratio, and {dollar}pm{dollar}5% for aerosol extinction coefficient. At 5 km, these values are {dollar}pm{dollar}12 K for temperature, {dollar}pm{dollar}4% for backscatter ratio, and {dollar}pm{dollar}100% for extinction coefficient. Suggestions to determine the cause of the offset and to reduce the relative uncertainties are also discussed.