STRATOSPHERIC DISTRIBUTION OF NUCLEAR DEBRIS
303
the last few years there has been an overlapping of balloon and WU-2
aircraft sampling at altitudes between 65,000 and 70,000 ft. There has
been no attempt to schedule routinely balloon and WU-2 flights; therefore H is unusual for flights of the two programs to sample the same
region of the stratosphere on the same day. Nevertheless, if we com-
pare results obtained from both programs at two locations regularly
sampled by each, we should detect any systematic discrepancy due to
sampler calibration or to analytical procedures.
The results of “Sr analyses of balloon and aircraft samples col-
lected at 65,000 to 70,000 ft at about both 31°N and 34°S latitudes during
January 1962 through May 1964 are plotted in Fig. 1. Over short intervals there appear to be systematic differences between results for the
two programs, but these differences are not consistently in one direc-
tion. They may result from differences in sampling altitude and from
the fact that the WU-2 samples are normally collected over a range of
5 to 20 degrees in latitude. When the data for the entire 29-month
period are considered, the agreement between the results for the two
programs is satisfactory.
We will assume that the calibrations of both the balloon sampler
and the WU-2 samplers are accurate for all altitudes and that data
from the balloon program and from the WU-2 aircraft are comparable.
Therefore we will combine them to obtain an estimate of the strato-
spheric distribution of nuclear debris.’
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1962
1963
Fig. 1—Trends in "Sr activity.
1964