TEMPERATURE SENSITIVITY OF DIFFERENTIAL ABSORPTION LIDAR MEASUREMENTS OF WATER-VAPOR IN THE 720-NM REGION

Recently measured properties of water vapor (H2O) absorption lines have been used in calculations to evaluate the temperature sensitivity of differential absorption lidar (DIAL) H2O measurements. This paper estimates the temperature sensitivity of H2O lines in the 717-733-nm region for both H2O mixing ratio and number density measurements, and discusses the influence of the H2O line ground state energies E", the H2O absorption linewidths, the linewidth temperature dependence parameter, and the atmospheric temperature and pressure variations with altitude and location on the temperature sensitivity calculations. Line parameters and temperature sensitivity calculations for sixty-seven H2O lines in the 720-nm band are given which can be directly used in field experiments. Water vapor lines with E" values in the 100-300-cm-1 range were found to be optimum for DIAL measurements of H2O number densities, while E" values in the 250-500-cm-1 range were found to be optimum for H2O mixing ratio measurements.