( 2 ) Danielsen, E. F., “Stratospheric-Tropospheric Exchange Based on Radioactivity, Ozone, and Potential Vorticity,” J . Atmos. Sci. 1968,25, 502-18. (3) Reiter, E. R., “A Case Study of Radioactive Fallout,” J . A p p i . Meteorol. 1963, 2 (6), 691-705. (4) Danielsen, E. F.; Bleck, R.; Shedlovsky, J.; Wartburg, A,; Haagenson, P.; Pollock, W., “Observed Distribution of Radioactivity, Ozone, and Potential Vorticity Associated with Tro-Dooause Foldine.” J . Geoahvs. ‘ . Res. 1970, 75 Ili),2353-61. ( 5 ) Mahlman, J. D.. “On the Maintenance of the Polar Front Jet S t r e a m , ” J . Atmos Sti 1973,30, 544-56. (6) Johnson. W. B.: Viezee. W.: Cavanaeh. L.: Ludwig, F. L.; Singh, H. n.;Danielsen,-E. F., “Measurements of Stratospheric Ozone Penetrations Into the Lower Troposphere,” Proceedings of the 4th Symposium on Turbulence and Diffusion, p. 355-62, Boston, Mass. January 1979; American Meteorological Societv. ( 7 ) Viezee, W.; Johnson, W.B.; Singh, H. B.. “Airborne Measurements of Stratospheric Ozone Intrusions Into the Troposphere Over the United States,” Final Report, Volume I. Contract CRC-APRAC Project No. CAPA15-76 (1-77), 219 Perimeter Center Parkway, Atlanta, Ga., September 1979; Coordinating Research Council, Inc.
William Viezee Warren B. Johnson Hanwant B. Singh SRI International
Menlo Park. Calif. 94025
Alcohol fuel Dear Sir: Your discussion of gasohol (ES&T, February 1980, p 140) omits three items which promise to be important to the energy input required to produce fuel and which I would like to see discussed. ( I ) What is the comparison with octane boosters? Alcohols increase octane without lead and without energy-intensive refining. Hut what are the numbers? (2) Alcohols can be separated from the mash catalytically; again, what are the numbers and who is developing the technology? (3) Solar energy can very conveniently be used on a small scale by farmers both for distillation and for drying. Paul Butkerert Freeport, N.Y. 11520
Marine pollution Dear Sir: This is an expression of our appreciation for the fine job you and your colleagues did on our article on marine pollution ( E S &T, January 1980, p 32). The organization you introduced in the representation of figures and tables was particularly gratifying. Donald C. Malins Director Northwest and Alaska Fisheries Center Seattle, Wash. 98 1 12 Volume 14, Number 6, June 1980 631