STRATOSPHERIC DISTRIBUTION OF NUCLEAR DEBRIS
PREPPrPrrerrerrrerprrrrrrrra rr perp rrr rr
5, ACTIVITY, DIS/ MIN PER 1000 SCF
104
309
65,000 FT
0 10°N
a
A 10°S
A 35°S
tiittilititiitititlitpitippriclipipti api
JJASONODJFMAMJJASONDJFMAMJJASONDJFMAMJJASOND
196]
1962
1963
1964
Fig. 6—Trends in °Sr activity.
VERTICAL DISTRIBUTION OF 29°Sr
The stratospheric residence time of nuclear debris should depend
to a large extent on the height of injection of the debris into the stratoSphere,
It is especially desirable to obtain evidence on the height of
Stabilization of debris from the 1961 and 1962 test series because of
the unusually high yields reported for several af the devices tested by
the U.S.S.R.° We believe that the vertical profiles of activity calculated
on the basis of the stratospheric sampling programs provide the information necessary to estimate these heights of stabilization.
The calculated vertical distributions of Sr at three latitudes at a
Series of times during late 1961 to early 1964 are shown in Figs. 7 to
9. Data for samples collected at 65°N are shown in Fig. 7. During
January 1962, following the 1961 U.S.S.R. test series, a strong maximum in the concentration profile was found at about 55,000 ft. At that
time, however, only low concentrations of 4Mn, '4Sb, and other prod-
ucts of neutron activation, which are considered to be tracers for one
or more of the high-yield devices tested* in October 1961, were present
in the sampled region. By June 1962 debris containing high concentra-
tions of these activation products was intercepted, generally at alti-
tudes of 60,000 ft or higher, and the maximum in the concentration
profile, although still af about 55,000 ft, was not as sharp as it had been