Lecture, three hours. Enforced requisite: course 201A. Anelastic approximation. Small-scale gravity waves in atmosphere. Critical levels. Kelvin/Helmholtz instability. Quasi-static oscillations of planetary atmosphere. Equatorial Kelvin and mixed Rossby-gravity (Yanai) waves. Baroclinic and barotropic instabilities in continuously stratified system. General circulation of atmosphere. Jet streams, eddies, storm tracks. Propagation of planetary waves. Wave-mean flow interactions. Noninteraction theorems. Letter grading.