9322480 Holton The objective of this research is the transfer of momentum, energy, water substance and other trace constituents between the troposphere and stratosphere by means of gravity waves and the mass circulation. Both processes will be investigated using selected numerical models of convection and general circulation, whose formulation will be guided by existing observations, including those of 50 MHz radars. In particular, a nonlinear model of the zonally symmetric mass circulation will be utilized to determine whether the mass transport into the tropical stratosphere is a consequence of remote effects initiated in higher latitudes or partially the effect of gravity wave drag arising from local convection or the subtropical jet stream. Most of the simulations will be accomplished using a two dimensional model, thought a few three dimensional simulations will be used to evaluate the merit of the former model.