Detection of tropospheric and stratospheric aerosol layers by optical radar (Lidar)

Summary The National Center for Atmospheric Research Lidar Sustem is briefly described. Data will be presented showing stratification and temporal variations of optical backscattering due to atmospheric aerosol up to a height of 40 kilometers. Short lived (less than 4 seconds) layers with thicknesses and spacing of 30 meters are routinely observed over the entire range of observation. A well-defined layer of temporal stability of several hours is very often found at the tropopause. The so-called 20 kilometer sulphate layer is found to be subject to variations in altitude, thickness, and assuming a non-varying size distribution and composition, in concentration. Significant and quasistable layers exist between 25 and 40 kilometers including one at the 36 kilometer leve which has been postulated by preliminary calculations of Mateer to be responsible for the blue and white bands observed and photographed by astronauts.Paper published by Journal of Geophysical Research75 (1970), 3123–3132.