Professors F. H. Busse and G. Schubert and Dr. R. Clever will conduct theoretical research on nonlinear thermal convection in flows heated from below. The goal is to elucidate the basic mechanisms in turbulent convection and to interpret the convective features observed in the earth and planetary atmospheres. The project contains four elements. 1. Three-dimensional time-dependent knot convection will be computed with emphasis on its relationship to the observed spoke pattern convection. Features such as mean flow associated, with some kinds of time-dependent knot convection, will be studied. 2. Convection with asymmetric boundary conditions is typical in nature, but has received little theoretical attention. Three- dimensional forms of convection such as those with an hexagonal or square lattice are expected to prevail. 3. Computations of three-dimensional convection flows in the presence of a mean flow with symmetric shear such as plane Couette flow will be extended to the case of Poiseuille flow. 4. Convection in rapidly rotating spherical shells will be studied with high resolution numerical codes. Results will be interpreted in terms of features of bifurcating solutions found in the cylindrical annulus model.//