Raman Lidar: Atmospheric applications

Water vapor plays an important role in the Earth's hydrological cycle, in radiation balance as a direct absorber of infrared radiation, and in atmospheric circulation as a latent heat energy source, as well as in determining cloud development and atmospheric stability. As a conserved atmospheric parameter in all meteorological processes except condensation and evaporation, water vapor mixing ratio is an ideal choice for studying many of the atmosphere's dynamic features.

Raman lidars have been used to measure water vapor mixing ratio profiles at high temporal and vertical resolution. Raman lidars sense water vapor to altitudes not achievable with towers and surface systems, sample the atmosphere at much higher temporal resolutions than radiosondes or satellites, and do not require strong vertical gradients or turbulent fluctuations in temperature that is required by acoustic sounders and radars. We plan to summaryize of Raman Lidar system's capabilities and achievements.

Analysis of highly-resolved water vapor mixing ratio and aerosol backscatter profile data from the archives of the Goddard Space Flight Center's Scanning Raman Lidar (SRL) and the Department of Energy's Atmospheric Radiation Measurement program Cloud And Radiation Testbed (CART) Raman Lidar (CARL) will be presented. The archive consists of intensive field operations made at the CART site in Oklahoma, data from the Convection And Moisture EXperiments (CAMEX) and several other field campaigns. We will present highlights of mesoscale structures, cloud-scale features as well as compare the instrument with several other standard instruments like the Microwave radiometer, radars, sondes, sun photometer. We will also address the viability of Raman lidar systems for long-term climatic studies.