0018933
best defined for Koa where it circulated -over: the afort foriatleast **
aday.
For Koa and Walnutthe altitude of the layer coincided quite closely
with the top of the cloud, whereas for Oak it was some 20,000 feet below
the top which was blown off rapidly by the strong casterly winds,
}
Since
the B-57D samples were taken from this stratum in each case, the criterion of sampling from a region which would not be receiving fallout from
any other source was easily satisfied,
Some altitude data taken in part from the wind and- _ temperature
tables in Appendix E are giveninthe Table 2..2:
TABLE 2.2
Approximate Altitude in Feet
Koa
Walnut
Oak
Tr opopause
57, 000
54,000
50,000
Light & Variable Layer
60,000 i
55,000
55,000
Cloud Top, Expected*
72,000
72,000
99,000
Cloud Top, Observed
65,000
61,000
70,000 - 75,000
Sampling Flights
60, 300
56,500
56, 300
* (Reference 59)
The suitability of the wind structures for fallout sampling elong height
lines can be most readily visualized by reference to the plan view, wind
velocity hodographs at shot tlme which are reproduced in Figures 2.9, 2,10
.