Viii. Radio Astronomy Academic and Research Staff

For some time there has been a discrepancy between theoretical and experimental values of microwave absorption in the terrestrial atmosphere. We felt that this is due to shortcomings in the theoretical treatment of pressure broadening when the significant overlap between adjacent lines occurs. Formal theories of pressure broadening have been given but have not been applied to the specific case of microwave energy transfer in the atmosphere where self-broadening and foreign gas broadening of 02 and H2 0 over the temperature and pressure range of the atmosphere must be included. We have adapted the theory for 02-02 and 02-N 2 collisions. We have found significant departures from results with previous simpler theory. In particular, we now note less absorption (Z15%) in the wings of the lines, and more (=8%) in the centers of the lines, which gives better agreement with experimental results. The computations are being extended to include all 02 lines of importance and microwave and infrared lines of H 20. Details of this work