抄録
Cs-137 fallout from atomospheric nuclear detonatin tests has been worldwide monitored since late 1950's. We analyzedt hese monitoringd ata statisticallya nd determinedt he characteristicso f their surface deposition.I n this analysis, the scale of space (size of compartment) a nd the accuracy of analysis (number of compartment) are determinedd ependingo n the global-scale dispersion of Cs-137. Mathematical model was developed and examined by comparing the numericals imulation with the falloutm onitoringd ata (includingt he data of Cs-137c oncentrationo f sea water).
The main results obtained in this study are sarnmarized as follows:
(1) Cs-137 deposition depends on the latitude zone but not on the altitude.
(2) Thep roposedm athematicaml odel is promisingf or evaluatingd ynamicp erformance of Cs-137 in global atomospherice nvironment and its surface deposition.
(3) Transportation rate coefficient from stratosphere to trotosphere, in trotosphere, and from trotospheret o land/oceani s highly sensitivet o surface deposition of Cs-137.
(4) Cs-137i s accumulatedm ore in surfacew atero f the North Pacifica nd NorthA tlanticO ceani n 1960' than othersa nd more in South Pacific and South Atlantic Ocean after 1970's. In deep ocean water Cs-137 is increasing more in Indian Ocean and South Pacific Ocean than the others.
