The Inter-Union Commission on Radio Meteorology of URSI and IUGG will hold a colloquium on ‘Waves and Turbulence in Stratified Layers and Their Effects on EM Propagation.’ The 1972 IUCRM Colloquium will be held in San Diego, California, June 6–15, 1972. The major topics of the colloquium are: origin of turbulence in stable layers7semi; remote probing of turbulence in stable layers; interaction of waves and turbulence; the nature of CAT and its predication; laboratory experiments; theoretical and experimental analyses of stability criteria; transport processes and spectral characteristics (anistropy, spectral saturation); and effects on E and M propagation. The topics will be treated in depth by review sessions, contributed papers, and working groups.