and then eastward within a very short time.
The lowest levels con-
tinued westward and the 18,000-foot trajectory appeared to curve
back towards the United States on the 28th, although the meteoro-
logical data is uncertain. Winds in the stratosphere up to the
level of the ton of the cloud were probably fromthe east, carrying
most of the mushroom westward.
Although almost a month elapsed between the first and second
bursts of the Castle series, enough debris from the first burst was
present to seriously interfere with attempts to trace the progress
of the second clowi by an examination of fallout data. For example,
an increase in deposited activity occurred at some stations in
Central and South America on March 31 and April 1, several days
before the meteorological trajectories would indicate the arrival
of debris. It is not certain if this is due to the complete lack
of meteorological observations in the Eastern Pacific and the winds
were really stronger than assumed, or that the debris was actually
(Note: Since all fallout data is extrapolated
from the Bravo burst.
to 100 days after the assigned burst, values aszizned to different
The extracclation factor derends
bursts cannot be comcared directly.
both on the day of the burst and on the day the sample was counted,
For the areas mentioned in this saragrarn, values assigned to burst
2 would have to be increased by about a factor of three if the debris
were assigned to burst- 1).
By April 2md and 3rd increases in activity are evident along the
Gulf Coast of the United States and certainly by the hth and Sth there
is good evidence that debris from this burst nas arrived over the
United States.
Again, as when fresh Bravo debris was present,fallout
seemed to occur irrespective of:the occurrence of precipitation.
The progression of debris westward from the test site appears to
have been more rapid than indicated by the Low-level trajectories
at 5,000 and 10,000 feet, at least for the first few days following
the burst.
‘“hether the arrival of debris at Yap and Koror on March 29
is a result of transrort of material westward in the stratoscheric
easterlies or in faster-tnan-observed low-level trades is not certain.
Again, as with Bravo debris, there was 2 marked tendency for the
fallout to occur in the tropical areas, with occasional incursions into
the United States.
2.3
KOON
Koon, the third burst of the series
tile
.
was detonated at
Biking 41620 GCT, Avril 6. 195. but cloudy conditions prevented
-ll-