Heating of the ionosphere with intense radio waves has been pursued vigorously over the last thirty years, primarily in the USA and the USSR. New, large facilities have been constructed in the USA and Europe. During the 1970's the branch of plasma physics known as weak turbulence theory and the theory of parametric instabilities were used to explain some of the unusual and unexpected results of the heating efforts. The present award is for a continuation of the application of this theory to interpretation of results, using a massive numerical modelling approach, involving extensive use of supercomputers.