-hfrequently, fails to reflect the bending of the pattern to the
e2st in northern Iisvada. Tha next figure contains a fallout
pattern, as the hesvy lines, which include the best estimate of
the change of the wind field in tins and in space.
It is
evident that incorporation of the changing winds provides a
better verification, This after-the-fact fallout pattern is
typical of most cases which have been attempted,
Intermediate Fallout
After most of the particles whose size are large enough to
have a significant fall velocity have been rezoved from the
atmosphere, the remaining particles are part of either the inter-
mediate or delayed fallout. For weapons which have been fired
at the Nevada Test Site, the interrediate fallout originstes
4n the troposphere since the nuclear cloud tops rarely penetrated |
the tropopause.
However, for larger calibre detonations, the inter=
mediate fallout may originate either from tropospheric or stratoespheric material,
If-the-stratosphere is—ths—sourcefor-soms-of
the-intermediste ndcease tar recite granite
should .be
greater-thansbout>microns for a
is-necestary ince
vertical
sphereA Le
y saad
For ¢
trian
the tclopcophere
specific gra
ra
2.50Tah
Bas
“sa theB Arba
‘ita e‘fat at originating
me bene
that t
etze
$01less
than-about20crons cheetheAergen-parthotesweotd-be-past of
thelocal-fattout.at the moment, 4 is-not possible to say with
confidence uhich source contributes the larger fraction for highe
yield explosions.
,
It 4s chsracteristic of tha motions in the atmosphere that air
masses are carried zonally, that is, around circles of latitudes,
ruch more rapidly than in the north-south direction.
both in the troposphere and stratosphere.
This is trus
The result of this
rateorological fact 4s the predominance of intermeciate fallout
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