CADMIUM-109 RESULTS FOR UP TO 20 KM

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JASONDIJEMAMJJASONDIJ FMAMJJASOND
1962
1963
1964
Fig. 1—Cadmium-109 concentrations above 19.2 km.

DISCUSSION

The first appreciable rise in !°°Cd concentrations did not occur
until the beginning of the southern-hemisphere spring of 1963 with

concentrations reaching a maximum value at the end of Novemberat
high latitudes in the southern hemisphere, This is approximately three

months later than the corresponding observations for the increase of

1022Rh in the northern hemisphere during the winter of 1959-1960. This

is consistent with the difference in timing between hemispheres for

the major winter disturbances in the polar vortex region.’ Concentra-

tions in the southern hemisphere dropped off markedly after November.
This decrease suggests that perhaps the November samples (44 and
48°S) represented a hot spot.
The northern-hemisphere winter of 1963-1964 has been characterized as being quite mild in terms ofdisturbances in the polar region,

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