Original Research Papers
A comparison of tritium and strontium-90 fallout in the Southern Hemisphere
Abstract
The histories of THO and Sr-90 fallout in the Southern Hemisphere are compared for the data available to June 1966.
The seasonal variation pattern (July–June) for THO in mid-latitude oceanic rainwaters is fairly closely reproduced from year to year, and peaks in late winter–spring. The peak coincides with the absence of the temperature inversion at the polar tropo-pause, suggesting that the stratosphere-troposphere exchange of the bulk of Southern Hemisphere THO fallout takes place over the polar regions.
For Sr-90 in mid-latitude rainwaters, the seasonal variation pattern is not so closely reproduced from year to year, but shows a broad summer maximum and winter minimum. It appears that the bulk of the bomb particulate products mixes southward within the lower stratosphere and enters the troposphere at mid-latitudes, the seasonal fallout variation being similar to that found for the Northern Hemisphere, but 6 months out of phase.
Consideration of the balance of THO in the troposphere leads to a relation which allows a seasonal variation pattern for the stratosphere-troposphere exchange of THO to be deduced from the rainwater concentrations.
Stratospheric measurements of bomb particulate products are taken into account in an assessment of Sr-90 southward mixing paths. An attempt is also made to deduce the origin and possible southward mixing paths for thermonuclear THO appearing in the Southern Hemisphere.
The history of the THO/Sr-90 annual (July–June) mean activity ratio is quite erratic, and it is not constant over the entire Southern Hemisphere at any one time.
References
-
Albrecht , F . 1951 . A. Monatskarten des Nieder-schlages im Indischen und Stillen Ozean. B. Monatskarten der Verdunstung und des Wasser-haushaltes des Indischen und Stillen Ozeans . Ber. des Deutschen Wetterdienstes 29 , 39 pp .
-
Aldaz , L . 1965 . Atmospheric ozone in Antarctica . J. Geophys. Research 70 , 1767 – 1773 .
-
Begemann , F. & Libby , W. F . 1957 , Continental water balance, ground water inventory and storage times, surface ocean mixing rates and world-wide circulation patterns from cosmic-ray and bomb tritum . Geochim. et Cosmochim. Acta 12 , 277 – 296 .
-
Begemann , F . 1958 , Tritium assays of natural waters . Final report , AF 18(600)-569. University of Chicago , pp. 21 – 24 .
-
Bolin , B . 1958 , On the use of tritium as a tracer for water in nature. Proc. 2nd U.N . Conf. Peaceful Uses of Atomic Energy 18 , 336 – 343 .
-
Brewer , A. W . 1949 . Evidence for a world circula-tion provided by the measurements of helium and water vapour distribution in the stratosphere . Quart. J. Roy. Meteorol. Soc . 75 , 351 – 363 .
-
Cambray , R. S. , Fisher , E. M. R. , Spicer , G. S. , Wallace , C. G. & Webber , T. J. , 1964 , Radioactive fallout in air and rain: results to the middle of 1964. U.K.A.E.A ., Harwell, Report AERE R 4687 , 31 pp .
-
Court , A . 1942 , Tropopause disappearance during the Antarctic winter . Bull. Am. Meteorolog. Soc . 23 , 220 – 238 .
-
Dobson , G. M. B . 1956 , Origin and distribution of the polyatomic molecules in the atmosphere . Proc. Roy. Soc. A 236 , 187 – 193 .
-
Dyer , A. J . 1966 , Artificial radio-activity, ozone and volcanic dust as atmospheric tracers in the Southern Hemisphere . Tellus 18 , 416 – 419 .
-
Ehhalt , D . 1967 . Tritium and deuterium in vertical profiles of tropospheric water vapour. Internat. Union Geodesy and Geophysics, XIVth General Assembly, Committee on Problems of Geo-chemistry, Berne, Oct. 2 (unpublished).
-
Eriksson , E . 1965 . An account of the major pulses of tritium and their effects in the atmosphere . Tellus 17 , 118 – 130 .
-
Eriksson , E . 1967 . The atmospheric transport of tritium, “Isotope Techniques in the Hydrologic Cycle” . American Geophysical Union, Geophysi-cal Monograph Series No . 11 , pp. 56 – 57 .
-
Feely , H. W. , Davidson , B. , Friend , J. P. , Lago-marsino , R. J. & Leo , M. W. M. , 1963 , The ninth quarterly report on Project Stardust. U.S. Defense Atomic Support Agency, Report DASA 1309.
-
Feely , H. W. & Bazan , F. , 1965 , Stratospheric distribution of nuclear debris in 1962, 1963 and 1964. Radioactive Fallout from Nuclear Weapons Tests, Proceedings of the 2nd Conference, Ger-mantown, Maryland, Nov. 3-6, 1964.
-
Feely , H. W. , Seitz , H. , Lagomarsino , R. J. & Biscaye , P. E . 1966 . Transport and fallout of stratospheric radioactive debris . Tellus 18 , 316 – 328 .
-
Friend , J. P. , Feely , H. W. , Krey , P. W. , Spar , J. & Walton , A. , 1961 , The High Altitude Sampling Programme. U.S. Defense Atomic Support Agency, Report DASA 1300.
-
Gow , A. J . 1965 . On the accumulation and seasonal stratification of snow at the South Pole . J. Glacio-logy 5 , 467 – 477 .
-
Grant-Taylor , T. & Taylor , C. B . 1967 , Tritium hydrology in New Zealand, Isotopes in Hydro-logy . International Atomic Energy Agency , Vienna , pp. 381 – 400 .
-
I.A.E.A. Tritium Lists, International Atomic Energy Agency, Vienna , Tritium concentration in rain, rivers and other water. Lists 1-6 .
-
Junge , C. E . 1958 . Atmospheric chemistry . Advances in Geophysics 4 , 1 – 108 .
-
Kalkstein , M . 1962 . Rhodium-102 high altitude tracer experiment . Science 137 , 645 – 652 .
-
Lal , D . 1963 . On the investigations of geophysical processes using cosmic ray produced radioactivity. Earth Science and Meteoritics, North-Holland Publishing Company, Amsterdam, pp. 115 – 142.
-
Libby , W. F . 1956 . Radioactive strontium fallout . Proc. National Acad. Sciences, U. S . 42 , 365 – 390 .
-
Libby , W. F . 1959 . Radioactive fallout, particularly from the Russian October series . Proc. National Acad. Sciences, U.S . 45 , 959 – 976 .
-
List , R. J. , Salter , L. P. & Telegadas , K . 1966 . Radioactive debris as a tracer for investigating stratospheric motions . Tellus 18 , 345 – 353 .
-
Lockhart , L. B. , Patterson , R. L. & Saunders , A. W . 1966 . Airborne radioactivity in Antarctica . J. Geophys. Research 71 , 1985 – 1991 .
-
Martell , E. A . 1966 . The size distribution and inter-action of radioactive and natural aerosols in the stratosphere . Tellus 18 , pp. 486 – 498 .
-
Münnich , K. O. & Roether , W . 1967 . Transfer of bomb 0-14 and tritium from the atmosphere to the ocean. Internal mixing of the ocean on the basis of tritium and C-14 profiles. Inter-national Atomic Energy Agency (Vienna), Symposium on Radioactive Dating and Low-level Counting, Monaco, 2-10 March 1967, pp. 93 – 104.
-
Newell , R. E. , Wallace , J. M. & Mahoney , J. R . 1966 . The general circulation of the atmosphere and its effects on the movement of trace sub-stances. Part 2 . Tellus 18 , 363 – 380 .
-
Nydal , R . 1966 . Variation in C-14 concentration in the atmosphere during the last several years . Tellus 18 , 271 – 279 .
-
Olsson , I.U. , Karlen , I. & Stenberg , A . 1966 . Radiocarbon variations in the atmosphere . Tellus , pp. 293 – 297 .
-
Picciotto , E. , de Maere , X. & Friedman , I . 1960 . Isotopic composition and temperature of forma-tion of Antarctic snows . Nature 187 , 857 – 859 .
-
Picciotto , E. & Wilgain , S. , 1963 , Fission products in Antarctic snow. A reference level for measuring accumulation . J. Geophys. Research 68 , 5965 – 5972 .
-
Pierson , D. H . 1961 . Transfer of stratospheric fission products into the troposphere . Nature 192 , 497 – 500 .
-
Roether , W . 1967 . Tritium in Wasserkreislauf , Doctoral Thesis. Univ. of Heidelberg , 67 pp .
-
Salter , L. P . 1965 . Stratospheric radioactivity in the Southern Hemisphere from 1961 and 1962 weapon tests. Radioactive Fallout from Nuclear Weapons Tests. Proceedings of the 2nd Con-ference, Germantown, Maryland, Nov. 3-6, 1964, pp. 409 – 421.
-
Small , S. H . 1960 . Wet and dry deposition of fallout materials at Kjeller . Talus 12 , 308 – 314 .
-
Stebbins , A. K . 1961 . Reports on the high altitude sampling program. U.S. Defense Atomic Support Agency, Report DASA 539.
-
Taylor , C. B . 1964 . Tritium content of Antarctic snow . Nature 201 , 146 .
-
Taylor , C. B . 1966 . Tritium in Southern Hemisphere precipitation, 1953-1964 . Tellus 18 , 105 – 131 .
-
Thatcher , L. L. & Payne , B. R . 1965 . The distribu-tion of tritium in precipitation. over continents and its significance to ground-water dating. Proc. 6th Internat. Conf. Radiocarbon and Tritium Dating, Pullman, Washington, June 7-11, 1965, U.S.A.E.C . CONF- 650652 , pp. 604 – 629 .
-
Vickers , W. W . 1963 . Geochemical dating techniques applied to Antarctic snow samples. General Assembly of Berkeley, Aug. 1963, Intern. Assoc. Sci. Hydrol ., Publ . 61 , pp. 199 – 215 .
-
Volchok , H. L . 1965 , Sr-90 Fallout in Antarctica, U.S.A.E.C . Health and Safety Laboratory, Report HASL- 161 , pp. 286 – 287 .
-
von Buttlar , H. & Wiik , B . 1965 . Enrichment of tritium by thermal diffusion and measurement of dated Antarctic snow samples . Science 149 , 1371 – 1373 .
-
Wilgain , S. , Picciotto , E. , de Brueck , W . 1965 , Strontium-90 fallout in Antarctica . J. Geophys. Research , 70 , 6023 – 6032 .