~ 13 -
variations by factors of no more than two to three at the most among
those areas where rainfall is moderate and heavy.
The other mijor hypothesis discussed at the fallout hearings was
that of Brewer of Fngland (6).
Machta described this theory of a slow
poleward circulation of stratospheric air from the equatorial regions
during which time the air my be carried to heights in the range of
100,000 feet. Accordingly, debris injected into the stratosphere at
11°, the longitude of the Pacific test aite, would be transported in
lesser amounts to the Southern Hemisphere with the lion's share moving
towards the Temperate and Arctic latitudes.
Machta states (26, 27) that
it is possible that the formation of new higher tropopauses by the passage
of storms in the Temperate latitude my entrap stratospheric air into the
troposphere, and that the break tn the tropopause found frequently in
the vicinity of the jet stream is a place of preferential exchange of
air between the troposphere and the stratosphere.
A corollary to this |
would be lesa stratospheric fallout near the equator where the tropopause
is very persistent and clearly defined as opposed to the polar regions where
it is generally lower and less distinct.
With present patterns of testing
this would mean a greater removal of stratospheric debris in the Temperate
and polar regions of the Northern Hemisphere with little or no debris coming
out near the equator and again sombut lesser amounts of fallout appearing
in the South Temperate and South polar regions.
Actually the observed distribution of strontium-90 is similar to
that discussed by Machta .
The only trouble here is that such a pattern
in the Northern Hemisphere could be in large part a reflection of the
fact that the nations who have done the most weapons testing to date