RADIOACTIVITY VS. HEIGHT IN NUCLEAR CLOUDS
631
consistent effect on the cloud heights. Evidently, the effect of the burst
height was masked by the influence of meteorological factors and/or
the errors in the cloud-height estimates.
Selected data” were added from other Pacific test series to aid in
drawing the mean curve and the curves for the estimated range of
cloud heights (see Fig. 1). Almost all the detonations in previous U. 8S.
1
80 LTT]
160
Le
PY TT PEt ge ta by]
TEdt yt iiee
ESTIMATED
-—
RANGE
“6 y49 J
aor
> 120
wf
ra
of
ia
\
—
an
_
” 100 --
—
>
—
<
So
|
< 80
—
=
GO
Fee
eee
so"
_
—_
o Op"
a
a)
_
a
0
VU
so Viltliil FLi titi ited ettil | bit tii
30 50
100
———— KILOTONS
500
]
—>-+
TOTAL YIELD
5
10
MEGATONS
50-100
Fig. 1—Cloud-top heights and estimated range for air bursts (180Y°%4
< burst height < 0.15 Hy) in a tropical atmosphere.
tests in the Pacific had been surface bursts, and the documentation of
nuclear cloud dimensions had been generally poor. The curves shown in
Fig. 1 are intended to be valid only for air bursts in a tropical atmo-
sphere and for burst heights less than about 15% of the expected cloud-
top heights. For this purpose, an air burst may be defined as a detona-
tion at an altitude equal to or greater than 180y°" where Y is the total
yield in kilotons. It is emphasized that there are no reliable cloud-top
data for yields greater than about 5 Mt, and the extrapolation of the
curves beyond this point represents little more than an educated guess.
Indeed, over the entire range of yields shown in Fig. 1, the dashed
curves indicate only the expected range of cloud heights for the stated
conditions
and should not be interpreted as representing absolute
a
limits.