Status of Global Radioactive-fallout Predictions 369 Lester Machta Some Aspects of the General Circulation of the Lower Stratosphere. . R.E. Newell and A. J. Miller 392 Cadmium-109 Results for up to 20 Km. 405 Stratospheric Radioactivity in the Southern Hemisphere from 1961 and 1962 Weapons Tests 409 M. 1. Kalkstein, A. Thomasian, and J. V. Nikula Leonard P. Saiter Tropospheric Mc Values in the Pacific Northwest and the Arctic Basin During 1964 . James A. Young, Nils E, Erickson, and Arthur W. Fatrhall 422 Fission-product Concentrations in the Troposphere and Lower Stratosphere over the Pacific Northwest Since 1962 428 Radioactivity and Potential Vorticity 436 P. H,. Gudiksen, G. L. Jones, W. R. Schell, C. A. L. Swanson, N. E. Erickson, and A. WwW. Fairhall EE. F, Danielsen Atmospheric Transport Processes Leading to Radioactive Fallout over the United States in November 1962 . Elmar R. Reiter and Jerry D. ‘Mahl man Relation of Upper Air Hemispheric Index Patterns to Seasonal Fallout Fluctuations. Jerry D. Mahiman Atmospheric Radioactivity Along the 80th Meridian (West) . . . Luther B. Lockhart, Jr., Robert L. Patterson, Jr., Alien W. Saunders, Jr., and Robert W. Black Variation of Fission Products and Natural Radioactivity in Surface Air . P, F. Gustafson, S. S. Brar, and S. E. Muniak Radioactive Rainout Relations on Densely Gauged Sampling Networks Floyd A. Huff .... . University of Oklahoma Program for Studies of Convective Storms and Scavenging of Radioactive Particles Walter J. Saucier, Samuel J. Hall, and Robert Y. Neilson Radioactivity in Precipitation: Case Studies from the 1964 Spring Season. Samuel J. Hall . .. . Air Cleansing by Convective Storms Donald F. Gatz and A, Nelson Dingle ix * 450 464 477 497 907 323 932 266